metres, but it’s pretty full. The Thames is now the cleanest metropolitan river on the planet, and supports 120 species of fish. We’re servicing forty-six countries across the world. It’s a damned big business. I could tell you about our sludge-incineration programme, but I fear I’d bore you.’
You’re right there, thought May. ‘Forgive me for asking, Mr Wilton, but what has this to do with Mrs Singh?’
‘I’m sorry, I tend to get carried away. Tamsin doesn’t like me bringing drains to the table, so when I find a fellow enthusiast . . . Ah, I think this is it.’ He pulled open another map drawer and tugged at a vast yellow sheet covered in dense, poorly printed lettering. ‘This was made in the fifties. It’s the last remotely accurate assessment of London’s missing tributaries and outlets, produced by the LCC, but parts of it are missing, or the courses have shifted. They need to be tracked because there are so many electrical cables and tunnels under the streets. London doesn’t operate on overhead systems. How do you track something that keeps moving? The truth is, we can only measure soil humidity and hope for the best. Look at what happened in Blackheath a couple of years ago—the roads simply caved in without any warning.’ He traced his forefinger along the route of the Fleet. ‘When rivers change course, strange things happen. If you don’t know there’s a river underneath, you might be inclined to start believing in ghosts.’
‘I’m not at all sure I’m with you.’
‘Well, you get sudden localized floods that appear as if from nowhere, and drain away just as quickly. There was a famous case back in the 1920s—some heavy wooden coffins were found moved from their pedestals in a sealed crypt in south London. There had been an unusually high tide that season. The water had seeped in through a tiny crack, lifted the coffins and drained back out. Water can travel fast, in very odd ways. It can be drawn up through a stone wall in dry weather, causing a damp spot ten feet from the ground. And they’re saying Mrs Singh was found drowned. When I looked at this, I began to wonder.’
He smoothed out a section of the map centred on the streets where they stood. ‘You see this large corner site? It’s a gastropub called J.A.’s. Changed its name in the late nineties. Used to be the Jolly Anglers, built on Anglers’ Lane. The lane’s not marked on this map as a river, but we know from local history that it was a popular bathing spot. The council filled it in some time around 1890. So we draw that in.’ He took a blue pen and ran a broken dotted line through the lane. ‘The only other Fleet tributary is marked here, two roads further over. But of course it must have connected to Anglers’ Lane; the river had to be fed from somewhere. Which only leaves Balaklava Street—or rather, the ginnel running behind the back gardens on the west side of the terrace, where Mrs Singh lived. It then crosses over the road, because it has to get down to its next known point of existence, at Prince of Wales Road. Which means that it flows right underneath Mrs Singh’s house.’
‘But you said it had dried up.’
‘I said that parts of it had, and parts had been bricked up, so that the river has to find ways to re-route itself. You have to remember that the Fleet was once over sixty feet wide here in Camden Town, and flowed to a great basin which is now Ludgate Circus.’
‘You’re suggesting we had some kind of flash flood, that the water poured into her basement and drained back out, not even leaving a damp spot by the time Bryant and her brother arrived the next morning? It doesn’t seem very likely. Where would the water drain to?’
‘Here, to the Regent’s Canal at Camden. We know the canal is topped up by underground pipes coming from the north. We’ve never drained enough of the canal to map what’s down there, and half of the Victorian plans went missing in the sixties—they made very popular framed prints for a while. We’ve had an unusually dry summer, followed by a freakishly wet autumn. I’m wondering if the extreme weather conditions unblocked some of the pipework. It might explain how Mr Copeland died as well. Suppose water suddenly filled that ditch, undermining his truck, then drained away just