The archive

The drive into Wales was fractious and slow. The motorway was mired in congestion and overwhelmed with traffic, so we slalomed across the map heading steadily westwards on a successively narrower corridor of minor roads, a routing which made me - the navigator - distinctly unpopular for a while.

I'll start at the end... I'm in the same coffee shop which I headed for at the end of my last walk. An old haunt, a staging post on the way back west after conferences in Bloomsbury or casing the City, worrying about appearing on too many CCTV feeds.

A month ago I didn't expect to be here in London. Arriving at the bustle of Paddington station on one of GWR's flagship new trains for the first time, I was a little early. The skies over Berkshire had seen a reassuring red dawn fade into a marine…

Walking the suburban margins of London I have stumbled - sometimes with surprise - across a range of housing estates. The explosion in population in the outer reaches of the capital travelled through the 20th century like a shockwave.

After the relative return to normal service last month, things didn't look so good for today's excursion. The weather, doubtful all week, had closed in over the last day or so, leaving a high chance of heavy rain.

I first encountered Tom Bolton's writing through two small but rather wonderful books, both about aspects of London which fascinated me. The first of these surveyed the familiar territory of the 'lost rivers' - a subject which I've happily wittered…

I was still smarting a little from last month's abortive walk, but things had started tolerably well. Despite some engineering works which saw me arriving in London around half-an-hour later than usual, the journey had been relaxing and I'd read and dozed my way east.

I calculated I had until about midday... The forecast wasn't good, and as I sped eastwards under steely, unrelentingly grey skies, I doubted my calculations. I was eager to get walking too and I felt anxious to cross London swiftly, emerging on its eastern edge in a silvery gloom.

Arrival in Erith did little to dispel the strange gloom I'd sensed about the place on my last, fleeting, Sunday afternoon visit. Back then I'd been content to assume it was shuttered and drab because of the malaise which descends on all British…