Tusker reached out with his right hand and grasped the umbilical. The diver shook his head like a dog in a tug of war but Tusker had got behind him and stayed there, matching his frantic twists and pivots. He brought the big knife up and sawed it through the umbilical and then the hose to his bailout bottle. There was a torrent of high pressure gas. He let go and watched as the diver weaved drunkenly along the seafloor, clutching the valves on his helmet, vainly trying to regain some breathing gas. Tusker could hear him grunting away the little gas remaining in his helmet, his torch light dancing crazily as he stumbled away. Tusker watched him fall to his knees and, with one hand, reach out to Tusker. Then, the diver slowly fell over onto the sea bed with a puff of silt, writhed briefly, then stopped moving. Tusker felt his gut wrench momentarily, then turned away.

The loss of diver comms and pressure would alert Dive Control aboard the Depth Charge and, no doubt, the second diver inside the wreck. There was no time to wait. Tusker had to move, fast.

The wreck loomed like a dead whale carcass, lying on its side with its long shadows of debris and coral dancing and swaying. Tusker caught his breath and took a second to check his pressure gauge. He was already past the first third of his bottom gas. He should be turning around now, but there was no point in dwelling on this. He was committed. He remembered the tight quarters inside the hull from his first dive here and quickly unclipped his decompression bottles from his harness and laid them down on the sand.

With three kicks, he lifted off the sea bed and was at the opening in the hull of the Vampire. The light inside was gone now: absolute darkness. He could hear the gurgle of a hard-hat diver’s gas supply somewhere beneath him. Someone was waiting for him to enter. Tusker fumbled for his torch and switched it on, quickly swinging its beam back and forth inside the black hole. Suddenly, from his right, just inside the wreck, a hand reached out and ripped the mouthpiece from between his teeth. He took in a gulp of seawater and swung his arm instinctively. The torch fell from his hand and dangled from its tether on his wrist, its beam bouncing wildly around in the darkness. With his left hand, Tusker took his second regulator, which hung on a rubber strap close around his neck, and pushed it into his mouth, coughing into it. He still couldn’t see the other diver but felt his presence close by.