It had been a challenging few weeks - the seasonal sickness that descends on all those condemned to office life had struck and left us tired and exasperated. To cap this, of all the body parts which could choose to exact sympathetic rebellion, my right foot was painful. I'd spent the last week of spasmodic coughing and sneezing poring over maps of Essex and I just couldn't find an easy way of advancing along the A13 - the walk was either too short to be interesting, or far too long for my current condition. Meanwhile, the day crept up on me strangely quickly. Rather unexpectedly though, a reserve plan sprang into being. I'm not sure how, or why I found myself idly looking over the OS Map of the Lee Valley - but it struck me it was time to return to the river I'd spent so much time mythologising over the last few years. I planned hastily: I'd walk into London rather than out, taking advantage of the parallel railways which flank the Lea Valley to make my escape if my range was limited by fatigue or foot-rot, and I'd start outside the M25. It made for a good long walk which symbolically cut another axis into that great circuit. The day dawned surprisingly fortuitously for a walk. The weather was perfect for walking, with blue skies flecked with cloud and a cool breeze. My foot too, appeared to have relented and healed somewhat. I tested my boots and found that they were far more comfortable than regular footwear had been. The journey to London was a relaxing, quiet pause - the first in a few busy weeks and I stalked off for the tube at Paddington in good spirits. A quick spin around the Circle to Liverpool Street, and then armed with coffee, onto a suburban service out into Hertfordshire. Rebranded as TfL Rail, the Overground Orange motif spattered across the decor, with a freight of spaced out kids nodding and sputtering home from a Friday night in the clubs. Over the rooftops of Bethnal Green and Hackney, then into the strange suburban hinterland which breaks like a spent wave on the western side of the Lea Valley. The Turkey Brook, passing under the line deep below signalled that it was almost time to alight, and to begin walking.

I was briefly disoriented on exiting the station - blinking at my map in the sunshine, I soon spied Trinity Lane heading off between ranks of suburban houses. The lure of possible supplies on the High Street was strong, but I had the urge to start walking. The surprisingly warm morning was wearing on, and I was still a little concerned about my walking speed and endurance despite having a pretty solid escape plan. In truth I didn't want to have to abandon a walk - it just wouldn't feel right. Immediately on entering the lane I realised I was walking a watercourse already. Sandwiched between the houses on my right and the road was a deep ditch, bridged by driveways into the pleasant looking suburban dwellings. Theobald's Brook, having emerged from under the road junction at the station, was leading me to the river. Being hazy on an exact route, I decided to follow Trinity Lane into the Lee Valley Country Park with the brook as my guide. Eventually the road dwindled to a lane leading to a level crossing over the railway from Cheshunt, and after a careful crossing I found myself in the park at last. The brook swerved away to join the Small River Lea, while the path opened into a vast greensward dwarfed by pylons. I recalled being taught as a small boy that electricity and water don't mix well - but here in the Lea Valley they are constant companions. Pressing on into the park I crossed the Lee Navigation near the Lee Valley White Water Centre, complete with its plaques bearing witness to Olympic renewal. The path rose here, with a good view along the quiet, emerald waters of the Navigation. There was a distant hum of traffic and a buzzing of insects. I was back in the valley, and glad to be here.

For a brief spell, I was walking beside the Old River Lee - the slow, stymied and meandering sibling of the Navigation which winds along the western edge of the valley. Shaded by trees, the emerald surface of the water rippled lazily as I approached the road near Waltham Town Lock. I had a choice as I surfaced - to continue on the banks of the river, or take the path beside the Navigation. I chose the western path - essentially because it appeared to involve less diversions around incomplete pathways, less complication - and perhaps less chance of temptation to deviate from my goal. Also, if I made it all the way, I'd be leaving the path at the same point where I parted from the valley over three years ago. It was a symbolic relinking, if nothing else. Immediately on crossing the A121 and descending to the bank, the character of the water changes. Hemmed in by a vacant industrial wharf in the midst of a dusty clearance process, the water is slick and dark. Stretching south, butting against the straight line of the Navigation are a range of warehouses with 'excellent motorway links' and claiming journey times of an hour to Heathrow. For the first time today I feel almost uncomfortably hemmed in by water - I sense the Small Lea lurking to the west, and only a narrow spit divides the Lea and the navigable channel here. Trees hang listlessly between them, and the surface shimmers with chemical rainbows and a faint heat haze. I'm suddenly reminded of The Waste Land:

The river sweats oil and tar

But the walk is pleasant. I'm not really hitting my usual pace - I'm just enjoying the cool of the river breeze and the sun on my face. It feels like a long time since I walked in sunshine. The rivers stay close here, as the shudder of motorway traffic begins to make itself heard. There is no great ceremony here, no arcing bridge. Instead a low, concrete bridge spans the collected rivers, the traffic just feet from my face as it shrills by. The road is flowing faster than the water, a lane of large lorries obscuring the sun before I reach the bridge. It's cool in the shade, and the slope under the pillars opens into a muddy lake of litter. A recently dumped, not yet torched Peugeot 206 awaits its fate beside a pile of clothes and soft-furnishings. It is surprisingly intact, and appears to have been driven here. The thought of off-roading across the marshes is absurd. Beyond the plain of waste, I spot a gateway leading up a rise and away from the river. I'm reluctant to leave the path - but I'm drawn to the light after being under the bridge. It's a slick, grassy scramble up the muddy slope on the edge of Rammey Marsh with just occasional tufts of coarse grass to aim a boot at - but I'm rewarded with a chance to be at close quarters with the M25 in a way I'd never quite expected. A huge Variable Message Sign curves over the carriageway nearby, and a bold blue board marks the border in capital fashion: HERTFORDSHIRE. As traffic shudders by, little more than pale streaks of colour and rushes of air, the infrastructure broods silently. The scale of the bridge, the towering pylons forming a lattice of wires across the road, the massive hulk of the signs - it is strangely awe-inspiring up close, out of the mediated frame of a windscreen. I paused here for quite a while, just watching the road while contrails crossed the sky. Here - for perhaps the only time on my walk - water wasn't the dominant force.

Scrambling back down the bank was more complicated and less dignified than the ascent, but I was soon back on the path and heading south. The river runs in three channels here - the Navigation and Diversion parting to envelop Enfield Island Village, with the Cattlegate Flood Relief Channel skirting the eastern fringes of the valley. I confess to being lost in the terminology here - ill-prepared for the complexities of the waterways I'm trying my best just to stay on course. But the lure of refreshment is too strong, and I climb the steps onto the bridge which leads into the former Royal Small Arms Factory. Inside the water-bounded compound it's a mix of old and new - long, low brick buildings which date from the island's former occupation rub gables with new housing stock, built in similar but slightly off-key styles. The overall affect is jarring and oddly creepy. There are few people around until I get to the tiny and ill-organised Tesco Express store - the only amenity here which is in business. I head back to the river with my purchases in hand. It's dusty and dry here, work still going on to build more housing on the southern edge of the site. I recall the tales of toxic dust when the main area was upturned and built on, and I try not to breathe until I'm safely in the shade of Swan and Pike Pool. I rest beside the water while across the cluttered, dirty pond someone does yoga silently. It feels calm and restful enough here - but that seems such an unlikely pursuit so close to the heavily polluted motorway air.

The valley changes character as I set off again. Turning south where the huge Enfield Energy plant dominates the view, the Navigation is a broad, straight canal. Right away we're joined from the west by a confluence of the Small Lea and the Turkey Brook, running in at a reedy, inauspicious junction. The Navigation's other sister streams have parted from us, running along the eastern edge of the valley and now separated by the vast hourglass-shaped expanse of the Chingford Reservoirs. The most northerly is the King George's Reservoir, with steeply raked grass banks separating countless millions of gallons of water from the rivers. This was, until 1951 an aerodrome. This flat, empty situation on the valley floor proved perfect for these experiments in watering a vast urban metropolis. A similar undertaking would almost never succeed now, risking strangulation by the twin hands of planning regulation and protest movement. The challenge of holding back such vast volumes without slippage and disaster resulted in a long-standing British dominance of the soil dynamics field. The towpath continues, skirting the minor kinks in the southerly course of the Navigation. An overflow channel leaves the canal, a concrete culvert full of mud and silt, hugging the perimeter of the artificial lake as a causeway carrying the A110 separates it from the William Girling Reservoir. The causeway is a passage from pub to pub - from Nags Head Road to Kings Head Hill, taverns celebrated along a route marking one of the few horizontal crossings of the odd, somewhat beleaguered valley. This lake - named for the chairman of the Metropolitan Water Board at the time of inauguration - is more elegantly tapered than its northern counterpart, the southern reaches pinched by the rising flanks of land which support Chingford and Tottenham. Looking west, a rank of four tower blocks at Ponders End dominate the horizon, rudely emphasised by the empty industrial lots between the river and the housing estates of Brimsdown and Edmonton. South of here, the western bank is dominated by the Lee Valley Athletics Centre - a pale shadow of what was meant to be the pre-Olympic dream: a revitalisation of the valley through sport has always been the officially preferred mechanism. At Pickett's Lock a crumbling boathouse is sheltering three preening swans, the plans for the 2005 World Athletic Championships long forgotten and eclipsed by the great events of 2012. The embarrassment of earmarking a site which was too difficult to reach and too expensive to develop is almost erased by later profligacy, by a project just too big to fail. There is a golf course now, man-made lakes, a sports centre to replace the original Pickett's Lock centre. But thankfully the river still runs undisturbed. The sun is riding high now and my forehead is starting to sting where I'm sweating. I fear I may be turning pink. I see virtually no-one on the path now except for the river-dwellers working on their boats and the occasional jogger. Most sane Englishmen are safely indoors, even though the April sun lacks the power of summer. I walk on.

Almost hypnotised by the long, yellow stone path stretching ahead, I'm surprised to hear the sound of traffic returning. The path opens into a vast stone chamber under the junction where the North Circular meets the Ravenside Retail Park. The complex web of slip-roads spans the entire valley, with a roundabout dominating the dormant space between the Lea and its navigable stream. As I pass under I instinctively turn to photograph daylight above me, penned in between the carriageways. I press the shutter as two huge birds spread their wings and head for the sky between the slip roads. Meanwhile a rowing boat filled with laughing Sea Cadets lurches and splashes under the A406. I'm inside the City's inner road necklace now - and any sense of rurality disappears. The walkway is narrow, a metal crash-barrier separating it from the dusty, unadopted mess of Towpath Road - existing only to serve a complicated jumble of businesses and the Arriva Edmonton Bus Depot, forced into the dwindling neck of land between the rivers. Dust rises from the passing buses, obscuring what appears to be an illicit trade in waste white goods. I'm pressed against the barrier for fear of cyclists who don't ring bells here. Thankfully, the River Lea soon rejoins and I'm on a thin spit of land between two wide, slow streams of water. The rank of pylons which have shadowed my route here from Waltham Cross have split, flanking the channel on both sides, placing me in an eerie procession. A genuinely electric avenue. A glance at the map shows an explosion of water here - the bulging circle of Banbury Reservoir is the last of the Chingford Chain, with the Walthamstow waters taking over the valley. I'll see less of these - they favour the eastern side of the Lea Valley, with only the Lockwood Reservoir sidling up against the River before I leave the valley.

This last stretch is hard going. It's been a hotter, slower walk than I'd expected and despite being mesmerised by the strange vistas of the valley, I'm tiring. A curving footbridge gives access to Tottenham Marshes and a series of well-used green links along the edge of Pymmes Brook. The afternoon is cooling a little, but the sun remains high - and couples push strollers and wander the path. The eastern bank is quieter until Stonebridge Lock where the only option is to cross the gates and join civilisation. The former café and toilet block is a focus for walkers - a place to reevaluate their limited post-prandial stamina and turn back before it's too late. Before they are walking the valley like me. I spot an entire family on a bench near the lock gates, the elder gazing down at the end of his walking stick. When I resurface from using the facilities they have crossed the lock and assumed an identical position on the western bank. My ceremonial guides as I embark on the last leg of my walk for today. The Navigation is busy between here and Tottenham Lock - the waterway filled with boats in various states of repair, from semi-sunken to beautifully decorated, and the footpath busy with walkers and cyclists. An alarmingly drunk man mis-steps toward the water, a passing family oscillating between concern and distaste. When I pass him he's facing inland and fumbling with his flies, smiling blissfully to himself. Saved again by instincts which defy his inebriation.

Despite knowing how close I was to my goal, Tottenham Lock came upon me unexpectedly. The gentle curve of Ferry Lane bridge and the strange oblique sculpture which sits beside it appeared in negative due to the glare of the sun - which now also bounced back at me from a range of tall apartments built since my visit in 2012. Pymmes Brook was now alongside me too - a stinking ditch in a divided concrete chasm, chasing its final few metres before being subsumed into the broader waters of the Lea. At Ferry Lane I resurfaced and crossed the road to survey the spot I'd left the river three summers ago. Aside from the near-completion of the vast development behind me, little enough had changed. But for me - everything had. I'd always anticipated picking up this walk in a northerly direction, heading away from the City and the repellent enforced buoyancy of the Olympic summer. Life took a different turn, and it seemed fitting to be coming back to civilisation, part of something bigger and more human from an entirely different angle. The last few steps to the platform at Tottenham Hale were as painful and frustrating as last time. There is no access to the station from the east, no one walking in from the lakes. It felt strange to be coasting across the wide expanse of green marshland near Clapton, after spending a day surrounded almost entirely by the waters of the Lea Valley and I realised I was catching probably my first glimpse of the familiar city skyline today as I headed back towards Liverpool Street. The wide swathe of water continues, paralleling the railway line - and I know that I'll need to return to walk the eastern reaches if I'm to fully understand this remarkable and confusing place.

You can find a gallery of images from the walk here.

It feels important to start where I left off. A month ago I looked out over Rainham Marshes with some trepidation. I'd almost resolved to carry on walking that day - to push on the few more miles to Purfleet. As I stood in much the same spot, I knew I'd never have made it if I'd tried. It was a hazily warm morning, sky like silver and slate, the marsh grass reflecting back none of its colour. I made a guess at the spot where I'd discarded my parents' key and paid a silent tribute. I realised with some dismay that I was now linked to this spot forever. My usual memory raid, in and out of a place before it could properly get under my skin, wouldn't work here. In fairness it hadn't worked much as I'd progressed into the east - and from the dirty chasm of Aldgate to the empty flood plains of Dagenham, I'd connected curiously easily with the terrain despite it being so far from my own experience. It was good to be back out here, contemplating a trudge across the gloomy marshes to the river. As I'd made the journey out from Fenchurch Street I'd doubted my ability to get quite as far as I planned today - I felt distinctly post-viral, a sweaty brow and a chest which fluttered oddly, causing fleeting thoughts of mortality and frequent checks of my heart rate. I brushed them aside with a likely unwise bacon roll washed down with more caffeine and focused on the walk ahead.

The first section of my walk felt true to the spirit and purpose of this unhinged enterprise as I strode out along a narrow strip of paved path between deep marsh grasses towards the A13, marching on elegant but strangely ominous stilts across the wetlands. The wind carried the sound away, and the traffic both looked and felt impossibly far-off, like a Patrick Keiller long shot of the viaduct. The road was just about the only thing providing some sort of form in this unsettling landscape, beyond that the land rose into an entirely artificial hill of accumulated landfill. The detritus of London brought to the fringe of the city to decay - safely distant from rate-paying habitation. I realise that I'm alone. I left the last of the dog walkers loitering suspiciously where the path which leads out to the viaduct parted from the local circuit of pale pink shit-sacks and suspiciously steaming tufts of grass. They stood around, fingers flicking over illuminated 'phone screens without clear purpose. Now there is just me out here. Me and cows. By far my least favourite animal - admirable from afar for their sheer improbability, their huge frames suspended from near-exposed spines while they lumber around a field of sub-standard marsh grass, nosing for the long depleted good stuff. The path headed directly towards the river, running parallel to a range of industrial buildings of uncertain purpose - only the last of them giving away its identity as a manufacturer of pre-cooked rice. The hill of waste was between me and the river, and it wasn't immediately obvious how I'd cross it. I soon found myself on Coldharbour Lane, a branch of the Ferry Lane Industrial Area - the wind-blasted, dusty thoroughfare I'd left at the end of last months' walk. The lane wound its way under the A13 and out to the fringe of the waste facility, before becoming this disconcertingly straight service road. Signs barked prohibition. The footpath was sequestered on the southern edge, a concession to the signposted walking routes which inconveniently bisect the trashlands, making them public when they are built to conceal. There was no traffic to beware of. A gatehouse up ahead seemed inactive, the barrier waving lazily in the wind. Just before the public/private boundary, a turning to my right took me along a rising, curved road which followed the outlet of the watercourse, the rice factory on its other bank. As the road rose, there was something about the flat, white sky which gave away the river's presence. A few more steps and the sweep of the Thames was revealed to me. To my right, the towers of the Isle of Dogs shimmered in the distance, while across the water minor industry struggled on on the fringes of Erith. But I was drawn to the east: the high towers of the elegant Dartford Crossing blinking back as it lurched over the river, the towers of the Proctor and Gamble works - it all looked so impossibly far away just now.

The car park was surprisingly busy: cab sleepers, dog walkers and bird watchers with flasks of steaming tea. Those who were awake looked resolutely out across the river. There was a faint sense of loss about the place. With the impressive expanse of the marshes hidden behind the vast mound of refuse, the path was the only escape. I felt almost guilty for feeling so surprisingly energised by the place. The ribbon of silver river called - this project so far had kept me away from water, my encounters with rivers were fleeting crossings at best. Immediately after I'd slipped through the gate onto the path I encountered a warning about straying into the waste lands. Beyond this, the path curved to navigate an inlet, and scattered within it were the hulks of concrete barges, abandoned unceremoniously after wartime service. The mossy, weed-draped hulls emerged from the inlet at crazy angles: some tipped their prows to the sky, others turned their shell-crusted flanks to the path. The forlorn scene was completed by a sculpture - John Kaufman's "The Diver: Regeneration". A strange wireframe figure, emerging from the mudflats, draped in weed and litter. A tribute to those who have worked the hostile estuarial environments out here, covered in the flotsam which keeps this an officially sanctioned danger zone.

The path hugged the river bank as I turned east again, and faced the estuary. The path was, predictably deserted here. Sandwiched between the silted fringe of the river and the fence of the waste facility, my walk was almost a textbook edgeland excursion. On one had I had the silver sheet of the Thames and the curious riparian foliage, on the other a dusty extension of Coldharbour Lane which thundered with heavy tractor units. WIthout their trailing loads, the cabs leered oddly forwards, imbalanced and purposeful, as they hammered around the corner and onto the edge of the plant. One thing both river and land had in common was rubbish. The wind-tossed overtoppings from the plant strung itself through the dried weedstems. Tucked between two tufts of grey-yellow grass I spied a fading nautical chart of the Thames, just out of my reach. An experimental energy generation plant belched out dark, organic sludge beside the road and generated the most curious smell: a sort of sweet, greasy earth, tinged with decay. After crossing a jetty serving the refuse station, I rounded Coldharbour Point and got a view of the territory ahead. Traffic on the bridge flickered in the middle distance, while across the river the waterfront of Erith dominated the view - a collection of modern apartments mimicking the traditional cliff of stucco-covered seafront buildings. Here I turned briefly inland, navigating the path as it climbed around the eastern edge of the waste mound. Rainham Marshes stretched before me - the A13 and High Speed 1 grazing the edge of the vision on low viaducts, which alternately rose and fell to cross each other just out of shot. Beyond the road, the village of Wennington and a smudge of red which signified the brick buildings of Purfleet. Between me and the distance? Nothing. An expanse of wet scrubland, marsh grass, ditches cut deep into the soil. Occasional human trappings were becoming integrated - rifle targets slowly discolouring to match the earth, bird-watching hides gradually becoming hidden themselves. The view from the slight elevation of the bund which protects the marsh was oddly spectacular and affecting. Looking back across the river, the flat and open foreshore was equally evident, emphasising the height of Dartford Creek Barrier which towered over the mouth of the River Darrent where it emptied into the Thames.

I spent quite a while chatting and lingering in the RSPB centre on the edge of the marsh, a curious half-glass camouflage block which couples a tea room and public facilities with a relatively luxurious hide for the discerning twitcher. The coffee was passable and the locals were interesting, if not terribly well informed about the river path. After being passed among a number of them, they proved knowledgeable enough about the route back towards London but they remained remarkably hazy on the eastward path. They knew I could get into Purfleet, but after that? Who knows. And to Southend! Why? It occurred to me here that they had me down as a more traditional kind of walker than perhaps I really am, and that they'd have seen landfill or a reeking soapworks as a barrier to passage. Not so far me of course, so I'd have to trust my nose. I left the impressive centre and set off over the bridge into Purfleet, passing the historic village green and the Powder Magazine - a survival from 1759. The river path dwindled to an access-only route to the inevitable stacks of river-front apartments, so I turned inland and found myself walking a surprisingly busy road through the bleak remains of the town. My first call was St. Stephen's Church - a long, low and fairly modern building which served as a chapel and church hall for the long-demolished Purfleet House. The assumed history here though is entirely myth - this was likely the model for Carfax, the house scouted by Jonathan Harker for Count Dracula. It seems a forlorn enough spot - but that has more to do with Purfleet's down-at-heel aspect than any supernatural force. Near the level crossing a single corner shop was open, its bored owner reading the classified ads at the back of a local paper with impressive focus. Anything to make time pass just a little faster out here. I bought water and chocolate and set off again. The station was oddly inviting - a near immediate escape from this odd little place which seemed to be almost entirely asleep on a Saturday afternoon. A bus sputtered by, picking up speed after a stop on route to Lakeside, the windows misted. Full of eager shoppers being drawn into the retail epicentre. I crossed the street, hedging my bets on which pavement would fail me first, and headed out of town. The road leading away from Purfleet is nestled at the foot of a chalky cliff, with new housing developments stacked against it and rising to meet it. Between the road and the river is a widening band of industrial land - including the vast oil terminal I was passing, realising I had a family link of sorts with the area. I didn't stop to investigate - navigating the cars parked on pavements, and choosing the right moment to slalom around them, avoiding the oncoming stream of tankers was something of a preoccupation. As I left the built-up area behind, I spotted the unlikely bulk of the Royal Opera House production facility in a large hangar behind a development of neat, new housing. It was incongruous and strange, but perhaps no more so than the continued existence of places like Purfleet at all. These edgeland towns which have been reduced to near hamlet status by virtue of the gravitational pull of nearby out-of-town developments seem improbable at best, and likely unsustainable. I wouldn't be surprised if I came back to find I'd dreamed Purfleet, written it forward from fiction and believed my own overcooked prose.

The official exit to Purfleet appears to be the strange dog-leg junction with the A1090. Suddenly, the environment is full of stimuli which have been absent in the village. The sky opens. The slender towers of the QEII bridge loom suddenly large, the oversized pylons carrying power cables across the estuary nestled behind them. HS1 crosses the road too, plotting its course to head under the river not far from here. Trains don't so much rattle as blast by, leaving a dusty gust of air in their wake. I take the exit for Thurrock here, feeling suddenly a long way from where I set out in the cool green calm of the marshes, but equally far from my goal. I'm almost disheartened here as I walk through rough scrubland, with a curtain of trees between the road and the plain of warehouses and refineries. But the bridge is upon me now: towering ominously above my route, a lattice of road and railway rising and plunging across the road. Passing underneath is unremarkable, and pushes me unpleasantly close to the thundering fuel tankers. I can feel the motorway above more than I can hear it. I feel my jawbone vibrating, my teeth touching in rhythm with the traffic above. The air is gritty with dust thrown up from the road, and cast down from the bridge - I feel it crunching between my teeth. The red ensign of the Ibis Hotel forms through the haze. I realise I've crossed another margin here: I'm outside the M25 now. London is definitely behind me, a punctured balloon which I'm escaping from in slow motion. This is a parody of the greenbelt - a rustbelt, industry not economically tolerated within the ring of concrete slowly decays here. Even the Waste Transfer Station had more purpose, more cachet than some of the cut-price tyre merchants here. Passing the Ibis is payment of homage to an unlikely literary landmark: much of the action of Iain Sinclair's "Dining On Stones" focuses on the hotel. It is a watchtower above the road, a proxy for the sublime tracking shot Chris Petit pulled off in Bristol for "Radio On". Sinclair's characters - often simulacra of himself - look up at the blank, reflective windows, or down at the equally impossible to read motorway junction. I try to look beyond the hotel to the sign gantries and wonder if it was here that Jack Whomes, brother of convicted Rettenden Murder John staged his traffic-stopping protest? This spot, where roads meet and join to form the last crossing of the Thames, is marked. It's a here-or-nowhere moment. A final opportunity to cross the water or remain on the north bank all the way to the coast. A crossroads of last chances. As a pedestrian though, I'm condemned to remain.

West Thurrock is a marginally energised take on Purfleet. A long string of communities, differentiated only by custom and local knowledge. Essentially the road is a long terrace, punctuated by views through to the riverside industry, which looms large over the Victorian homes. My feet are starting to drag, and a detour into the industrial zone to find the tiny church of St. Clement, eclipsed by the soap factory, just isn't practical today. As I cross the unmarked boundary of South Stifford, the unmistakable waft of skunk permeates the air. A front door bursts open, and the lazy Saturday afternoon drone of traffic is suddenly interrupted by a volley of barks. A squat, balding character weighed down by heavy links of plated chain swaggers into the path with a fistful of dog leads. Ahead of him, a pack of short-legged, bull-nosed terriers slaver and skitter, blinking in the light and scuffling for freedom. He presses a phone to his ear and yells into it. I wonder how I'm going to write this into my journey without pressing all the stereotype alarms? A group of Burberry clad young guys head out from a side-street and knock a nearby door which pulses with low-frequency reggae. No-one answers so they slink off, laughing and kicking each other from behind. I feel like I'm in a cartoon of Essex. All the mis-spelled sign boards of Dagenham, the mock-country pubs of Barking, all the things I could edit out of the Essex I'd experienced - and all of the liminal spaces and curious corners I could highlight in their places! But now this blew my cover. In the gravity of Lakeside, the gusting litter reflects its franchised restaurant chains rather than the line of local chicken take-aways. I'm an imposter here. I'm not spending any money.

I realise that I'm arriving in Grays. There's no sign or specific moment of transition - this road feels endless, though I've begun to wonder if I'm inexplicably looping by the same few terraces, the same tired little newsagents? The only real signifier is the change in the roadsigns - Southend is now a destination. Out of the gravity of London, beyond the skin of the Orbital Motorway, it is again acceptable to refer to regional destinations. I'm fooled into thinking the end of the line is nearer than it has seemed for most of today, and I'm spurred into a final push. I don't really get into the Town Centre, skirting the edge towards the station and seeing the square, modernist tower of the State Cinema glowering over the bus station. I'm tired - so tired I misread the station completely - heading for the bay platform with an infrequent service via the route I've travelled today. I realise there is a train soon via South Ockendon, but it's on the other platform. I stumble idiotically around looking for a way to cross, before finding the dank subway just as I'm about to give up and wait for the next train from the bay. I'm not sorry to escape Grays, even with the Lakeside-bound hordes sharing my train. It's been a long, tiring and dusty day which has already left me feeling confused and curious to research these odd surroundings. I'll need to come back here to pick up this route at some point, but I'm a little afraid of straying out into the open country of Essex. The rural gothic of the mysterious east beckons, with its freight of folk tales ancient and modern.

You can find a gallery of images from the walk here.

In some ways it felt strangely familiar to be heading out at the crack of dawn, on the very first possible train of the day in pursuit of new track, joining the surly nightworkers and early airport crowd. But in many ways it was far from it - deposited at the station via a warm car ride, and knowing I'd be picked up at the end of my day was quite a new experience. So too was doing this directly from home, rather than from a bolt-hole somewhere else in the country - a hotel room in Crewe or Birmingham seemed to be almost home for a good few years of my life. It was though, surprising how quickly the sense of excitement and contentment of a day on the rails returned. I think I'd almost worried I'd lost the thread of this hobby somewhere - but with the sun just rising as I was deposited in Bristol it promised to be an interesting day. I settled into my familiar seat on the Cheltenham-bound 1M21 like I'd never been away.

Arrival at Cheltenham was absurdly early. I'd not quite believed the timings when they were tentatively announced and then withdrawn, so I'd gone for an excellent cheap fare on my old stalwart services. This meant a pleasant linger over coffee and breakfast in the station buffet, watching the world go by. I've missed this a lot I think, and in some ways I replace it with my local coffee shop jaunts or time in London, but there's nothing like watching people going somewhere - some are agitated by running to a schedule other than their own, some are excited - a first trip for a young, wide-eyed youngster on a train perhaps. Some are clearly upset, bewildered or just beaten down - and there are a fair few intriguingly mysterious types too. Perhaps I read too much into the faces of people impatiently waiting for watery lattes in Cheltenham? Perhaps though that's one of the things which has always fascinated me about travel - who are these people, and why are they out here doing this today? As I started to get myself organised for the trip - copied Quail pages, Baker atlas to hand etc. - I realised there was a really excellent independent coffee shop a stones' throw from the station. Next visit, I reassured myself, and headed out to the platform.

It's equally interesting how similar the platform felt as we waited for the tour to arrive. Bewildered normals wondered why all these odd, excitable folks had suddenly appeared, tripods were assembled at the platform end. At the north end, where messages had told me our coach would be, there was a more subdued and discerning crowd. They all seemed to know each other - and I felt out-of-the-loop. Of course this is because I was boarding at a station I used very little. If I'd appeared at Crewe or New Street, I'd probably have ended up in a spirited conversation with someone who didn't realise I'd been away from the rails for three years or more and just assumed it had been a while since we'd crossed paths. But just now I felt a little pang of panic. How would today pan out? Before I could get too deep into that concern, the familiar whisper of anticipation passed around the platform. In the distance, a red speck shimmered on the horizon. 59202 was approaching with the tour almost exactly on time. It's like I'd never been away after all.

It was great to catch up with the folks on board - people who I'd spent countless hours with over the years in all kinds of places - sometimes interesting, sometimes hilarious, sometimes whiling away boring scoots back to Crewe or Doncaster in the dark after a day out. Things hadn't changed much - and we were soon discussing the day, the railway scene and catching up on events pretty effortlessly. The tour had extremely lazy timings, and aside from some interesting shenanigans switching lines around the curve at Westerleigh, all went smoothly and I was soon back at Temple Meads. A break here to attach 59001 to the front meant a chance to grab coffee, take a picture and to enjoy the atmosphere of the station with a 'proper' train for a change. We were soon back on board, and heading towards Bath in gloomy and damp conditions. Taking the curve to Westbury and negotiating the through line behind the station, we slewed across an unfamiliar connecting line to head for Frome. I was really only a few miles from home at this point, but I felt like I'd travelled more today than for a long while. Our first call was at Whatley Quarry - new track for me - and after a surprisingly swift run up into the Mendips we soon came to a halt outside the sheds. The Pathfinder publicity machine had - as usual - ground to a halt now, and there was no announcement about what was happening at all. A slow trickle of vestibule-huggers passed through the carriage, and soon we were moving slowly back towards the mainline. Apparently at this point we were being propelled by the resident shunter - but we'd never have known! After a brief halt to detach our additional power, we headed back to Frome, reversing again and heading south through the town's rather quaint wooden train shed on route to East Somerset Junction. From here, it was a slow, wet crawl towards Merehead Quarry. I'd been here before - or at least close by, and we set out by following the same curve towards Cranmore before coming to rest in the long siding beside the through line. Again, no announcement but we were soon reversing between rakes of wagons on the northern edge of the triangle. Apparently, this road was obstructed, so we retraced our steps forwards into the siding, then back around the western side of the triangle. Here, back at the entrance to the complex we forked right and crept around the eastern curve a short way towards the A371 bridge which was our destination. But we didn't quite make it. In fact those at the rear of the train would barely be past the junction. As we sat waiting for a water tender to tank the coaches, an announcement was made about what we'd done and what mysterious engines were on the shed we couldn't see! I shouldn't be surprised - it is perhaps always like this on these trips, but it was a little deflating to sit in the rain for forty minutes when we knew there was track we hadn't done.

The return trip to Bristol was a chance to relax and chat with the folks from up north who I don't get to see too often, a chance to share a few bottles of beer and to speculate on when we might all be out on the same trip again. It had been a fine day out despite the challenges and disappointments - which are of course, all part of the hobby I remembered. Leaving the train at Bristol was tough, the urge to plough on into the night and up the Lickey Incline was strong - but for the first time ever I had a reason to be heading home after a trip. Some things have stayed the same these past few years, but some are very, very different!

I woke early this morning, despite trying not to. It's become my custom on our more urban breaks to use the golden morning hours wandering deserted city streets or staking out turgid waterways while my wife prefers to sleep in. We're agreed that each other's chosen way of spending those hours between the time that fools and decent-minded people rise isn't for us - another way in which we complement each other it seems. In fact, I'd worried a little that being out here in the countryside, out of easy range of civilisation would leave me pacing the room in frustration at the waste of these quiet early moments. Once I'd accustomed myself to being away from home I remembered the rather splendid location we were in, and padded over to the patio doors at the end of our huge room. We'd gone to bed on a wet, dark February evening with the lights of Worcestershire twinkling happily in the rain - but I woke to a wonderful vista - the Severn valley fell away from the Malvern Hills, a vast pool of mist capped by the distant, purple smudge of the Cotswolds. A patchwork of green and yellow could just be discerned through the cloud, and above it all a weak but persistent winter sun was rising. It was a beautiful scene, and I quickly dressed and slipped out onto the little balcony with a fairly horrible coffee for company.

I'd intended to read, or to write - but for the first time in a very long time I felt content to do virtually nothing but look. I watched the sun rise, the first time this year that I'd really felt it's warmth, and start to burn off the mist. I watched the first, intrepid birds braving the chill and diving for worms in the dewy grass. Slowly people began to stir and wander towards the breakfast at the main hotel building in pairs, holding hands. It was Valentines' Day and we were part of a band of people getting away for the weekend. For me though it was an anniversary - three years ago I was preparing to head for Seattle - a nervous, painful time of fear and uncertainty which seemed a world away here. Particularly here, because this place - these hills specifically - had fascinated me from an early age. From my school playground I could see across the flat plains of Northern Worcestershire towards the Malverns. They were a dark, ominous presence on the horizon, and I remember a game I instigated where we were tribesmen bowing down to the hills. I really don't know where I got the idea, probably some comic or history book - but little did I know how I'd be venerating the topography all those years later. I had relatives who lived on the other side of the hills, and travelling to see them was a delight - would we skirt the hills on the dull, flat road or take the exciting Wyche Cutting with it's switchbacks and hairpins, and it's curious amusement arcades and attractions lining parts of the route? I remembered too a journey with my father, when I insisted on dragging along a Tonka tipper lorry. I recall we walked up a dry, scree-covered slope and he paused to let me repeatedly fill the truck, run it a way along the track and dump it's contents. It felt like a rare moment of calm in my dad's life - a time when he wasn't rushing to work or snoozing over his dinner.

Later, we walked into the hills together from the southern edge at British Camp. The track runs along the ridge, rising gently at first then undulating as it climbs. From the first peak, the views were sublime. The sun had stayed high and surprisingly strong, and up here the wind was blustery and refreshing. I asked if we should turn back, but I was assured we could go a little further. Finally the views opened on both sides: to the west, the shadows of Welsh mountains adumbrated the rolling country of Herefordshire, and to the east Worcestershire's typically English blanket of farmland rolled towards the Severn and the Avon. We stayed up there for a while, letting the wind whip our hair in our faces and thinking about the journey we'd both been on to get here. I realised too, as I looked out over my home county that I missed my father terribly - more than perhaps I ever expected. I missed both of my parents more in fact than I'd dared to admit to myself over the past year. But I wasn't alone up here - and that is perhaps the most surprising thing of all.