One

'Tyldesley? Tyldesley? Are you reading me?' There might have been a trace of panic in Jane's voice but the helium disguised it. He gave three quick tugs on the security rope binding them all together and made a start for the pair of two-man diving bells, twenty feet east. There had been some failure, some catastrophic failure. Fear swelled inside him, like decompression sickness. He had seen a man with the bends once. You don't forget that. All of the limbs withdrawn into a core of impossible pain. The welter of blood at every orifice, fizzing bright red. Bubbles opening in the jelly of the eyes.

He checked back a couple of times on that shambling race for the bells. He could only see Stopper, but the silver streams of bubbles rising behind him suggested that Rae and Carver were at his heels.

Jane reached the second bell and swung himself under. He rose through the open hatch, pulling himself in with arms that felt too weak to support him, or anything else. He was shivering, trying to shoulder off his bale-out bottle when Stopper's head emerged into the wet porch.

'Electrics?' Stopper asked, when he'd levered off his helmet.

'Must be,' Jane said. 'Thank fuck the back-up kicked in or we'd have been sucking in nothing but the taste of rubber.'

'What do we do?'

'I'm calling this an emergency,' Jane said. 'How about you?'

'I second that.'

'We get back to the habitat,' Jane said. 'Decompress. Then kick the cock off whichever twunt sat on the off button. Are the others in?'

'Already ascending,' Stopper said.

Jane sealed the inner hatch and turned his attention to the depth gauge, so it was Stopper who saw the first of the dead fish drifting past the portholes. 'Look,' he said. His large goalkeeping hands kept wiping and rewiping the Zappa moustache that bracketed his tight nervous mouth. Shoals of dead fish – cod, coley, pollack – were raining down around them.

'What's it look like to you?' Stopper asked Jane.

Jane shook his head. Visibility was improving as they rose out of the black of deep sea into the blue surface waters above 200 feet. Blood billowed out of the fish from the gills and the eyes, swinging in the pulses of current. 'Explosion, maybe?' he said. 'Poison in the water?'

'Poison wouldn't put our comms out,' noted Stopper. 'But maybe they're unconnected. Shall I try the radio in here?'

'Already did,' Jane said. 'It's dead.'

'We need to get back to the Ceto,' Stopper said. 'We need to get inside.'

'It's OK,' Jane said, and the words died between them.

'What if there's nobody up there to disconnect us from the stage?'

'Seriously, Stopper, give it a rest,' Jane said. 'What do you think happened? Everyone fucked off and left us on our own? Check the pressure. I don't want us going fizzy.'

'Pressure's stable,' Stopper said. And then: 'Oh my God.'

A human body. And then two, three more. Drifting down through the water, arms outstretched as if they were skydiving.

'Oh, Christ,' Stopper said. 'Who's that? Is that Terry Mead? What's going on?'

Jane joined him at the tiny porthole. Together they watched as what looked like black cobwebs funnelled from the sockets of Terry Mead's face – his mouth hanging vastly open as if it had been dislocated, clouds of blood pumping from it like a belching factory chimney – before he twisted and tumbled away from their field of vision. More bodies sank around him. Jane counted a dozen before Stopper, weeping, dropped to his knees.

'We're dead,' Stopper said, hysteria threatening to take his voice to a point where it could not be heard. 'That poor man. All those poor fucking men. We're dead.'

'It must be an explosion,' Jane said. His own voice was rendered toneless by the panic. 'But then, I don't think so. Look at their clothes. Nothing got torn off.'

'They jumped? A fire?'

'Maybe. Maybe a fire. In the comms room? Spreading to the generators? It would explain the blackout. It would have to be a nasty bastard to make men jump.'

'Jesus,' Stopper said. 'Who's going to plug us in?'

They ascended the rest of the way without speaking. The bell filled with hard hot breath. As they neared the surface they braced themselves. The bell began to rock violently on its hoist wire, more so than was usual when they lifted out of the wet and into the air. The great legs of the platform seemed to be swaying in the current, as if about to pull themselves free of the bed and start walking.

'This is not good,' Jane said.

The bell broke the surface and he had time enough to see the service chopper hanging from the helipad with its rotors torn off. The portholes became caked with a sudden thick black residue. He hadn't seen anybody else on deck and had no idea what had happened to the bell containing Carver and Rae. Their own bell swung about on the end of its cable like a wrecking ball in search of something to hit. The abandon-platform siren was coming to him, shredded by the wind to an ineffective stutter.