The Water Room

The alley was under several inches of water at one end, but the raised area around the grating was virtually dry. The lid had been removed and cast aside. Bryant pointed to the iron rod sticking out of the turntable at the bottom of the shaft. ‘You see?’ he crowed. ‘He’s kept this path free for himself, and now he’s gone down to follow the re-routed channel. We’re going to lose him if we’re not careful.’

‘Could you explain what’s going on, sir?’ asked Bimsley, fighting to stay balanced in the shifting mud.

‘Later,’ Bryant promised. ‘Help me down.’

‘Are you sure it’s safe?’ Bimsley asked.

‘At the moment it’s still passable. The volume can rise at an incredible speed in times of heavy rainfall, but it also runs away fast. There are emergency drains which open to reduce pressure. I’m more worried about what will happen if it stops raining.’

‘Why?’

‘The levels will fall and switch from the overflow conduit back to this route. Which means these smaller corridors will become inundated once more.’

‘How long have we got?’ asked May.

‘That depends. The channel will take Tate directly to the St Pancras Basin, but if the rain eases up, the tunnels could switch back in just a few minutes.’

‘Then we should go overland.’

‘We have no way of tracking him from above, and to do so would be to miss the entire point. I think he wants us to follow him down there. We need the final piece to this.’

‘Then I’ll tell Janice and Meera to follow above ground, and keep us apprised of the weather conditions.’

‘How will we know where Tate’s gone?’ asked Bimsley, reluctantly lowering himself into the steaming drain.

Bryant smiled and held up his river map. ‘He left us a guide. Let’s get going.’

The first two tunnels were dry and easy to negotiate, but by the time they reached the third, it had been joined by another channel from a different tributary, this one bringing in floating islands of animal fat from a riveted lead pipe. The stench of rotted meat and sewage caused Bimsley to throw up his lunch over a blocked drain.

‘The construction of these tunnels is remarkable,’ Bryant enthused. ‘Look at this metalwork, you don’t find craftsmanship like that any more. And the decoration-why would anyone bother to put a neoclassical bay-leaf- garland motif around an arch that no one will ever see? That’s Victorian pride for you.’

‘Jesus, there’s bloody great big rats down here.’ Bimsley hopped on to one foot and banged his skull on the ceiling, shattering calcified stalactites as a bedraggled squeaking creature with matted fur shot past him.

‘Don’t be such a baby,’ said Bryant, turning the map around. ‘John, we need to concentrate all our lights, please.’

They forked left at a pair of yellow-brick arches coated in slender black tree roots.

‘We must be under Prince of Wales Road, heading toward the Regent’s Canal by now. Look, there are plaques.’ May pointed to the conduit’s brass nameplate bolted into the wall, a subterranean echo of the street names on the roads above.

Bryant’s torch-beam fell on what appeared to be a bundle of rags. ‘Tate’s jacket. He wants us to follow him.’

‘For the life of me I don’t understand why,’ said May.

‘Oh, he’s been waiting for this since the rains began.’

‘Does Mr Bryant know something we don’t?’ asked Bimsley, confused.

‘Mr Bryant always knows something we don’t,’ May admitted. ‘We’re going to need inoculations after this.’

‘Perhaps, but we’ll have learned something new.’ Bryant shone the torch over the tunnel arch. A wider channel ran crossways, like the junction of an arterial road. Shallow, cleaner water was flowing fast through it. ‘I don’t weigh very much. Think we can get across that?’

‘Hang on to me. Bimsley, you’re the heaviest, lad-you lead.’

The trio clutched each other’s hands and waded out, but Bryant was nearly pulled off his feet. May and the detective constable yanked him to the other side like parents controlling a recalcitrant child.

‘Look at this.’ May pointed to the wall beside them. ‘One of your fail-safe conduits.’ He slapped his hand on the riveted steel panel, layered with grease and grooved at its base to shift around a matching steel arc, like the flood gate in an underground station. Behind a grille at the top, water was rushing away into darkness. ‘If the water rises too high, it’ll come over and re-flood this tunnel, creating a run-off.’

‘Some of these tunnels look dry,’ Bimsley pointed out.

‘I don’t think we’ve reached the part of the system designed for peak flooding yet,’ said Bryant. ‘We’ll know it when we see it.’

From here the floor sloped downwards, and they found themselves going deeper. ‘According to this, there’s an emergency escape drain above us, but I don’t see it.’ May waved his torch about.

‘There,’ said Bimsley, illuminating a narrow round shaft far above them. ‘It looks like the ladder has rusted away and fallen in.’

‘That’s reassuring.’

Following the map to the St Pancras Basin, they turned into a narrower ramped tunnel with slender iron platforms on either side. ‘This is part of the system newly exposed by the flood switches,’ said Bryant. ‘Look at the walls.’ They showed clear signs of long-term immersion. Strangely, the stone floor beneath their feet was less slippery, and the air smelled healthier. ‘Nothing’s had time to stagnate here. It’s probably been kept full just coping with the natural run-off of freshwater from Hampstead Heath and the other high areas above the city. It isn’t wide enough to cope with severe flooding, but it’s fine for everyday use. Wonderful workmanship; not a stone out of place. Beautiful bevelling.’

Bimsley’s radio crackled, making him jump. ‘The rain’s easing up,’ warned Longbright. ‘You’d better start heading for the nearest exit.’

‘We must be nearly there.’ Bryant waded on ahead. ‘The light is less dense.’

He was right. A faint sickly glow changed the colour of the walls before them, but as they approached, they found themselves entering a network of claustrophobic culverts, each one barred at the end.

‘We’ll have to turn around,’ May warned. ‘This one’s a dead end too.’

‘Interesting,’ said Bryant, seemingly unconcerned that they might be swept away at any minute. ‘I’m assuming that Tate is down here looking for something that has been unexposed for some thirty years, and I would have thought that this was the most likely place for him to be. The tunnels fill to their highest level, then empty, washing everything out this way.’

‘There’s no sign of him.’

‘He must have left some kind of trail. Keep looking around.’

‘Bimsley, how long since it stopped raining?’

‘Twelve minutes, sir.’

‘The levels will be falling. We should try to find an exit. Call Longbright and find out where the nearest drain shaft is, would you?’

Bimsley tried his phone, but failed to locate a signal. ‘No response. We’re in pretty deep ground.’

‘So we’re on our own. I wouldn’t fancy our chances of climbing those slopes back up. We’ll have to go on,’ said May.

‘Very interesting,’ said Bryant approvingly. ‘The Fleet was choked off by the expanding metropolis, but its waters still ran, albeit at a fraction of their former power. And at the highest flood levels, the water would fight to find a way around the obstacles. The system is beautifully simple when you think about it. The engineers knew the floods were cyclical over decades, so they allowed for the Fleet to return by a series of self-controlled gates that can only be opened by a specific volume of water. Under such conditions, the river cuts a path all the way through the local district conduits to form a single united flow heading to Camden Town and Clerkenwell, following the old route just as it used to, before emptying out into the Thames.’

‘Yes, Arthur, and as soon as the level drops and the weight recedes it will switch back, leaving us, all too literally, I fear, dans la merde. So can we push on?’

‘Let me see the map again.’ Bryant held it beneath his torch.

‘I can hear something,’ warned Bimsley, putting his ear as close as he dared to the wall. ‘It doesn’t sound