She might have had only one previous encounter with Pearce but it was enough. She wasn’t going to let him get one up on her. Even if it meant breaking all her professional rules and going deeper than fifty, she was damned if she wasn’t going to complete the search. There was a sign set in concrete to her right, the words covered in algae. Danger: depths exceeding fifty metres. Random checks on dive computers are in force in this quarry. Do not dive beyond your capabilities.

Good place to hang your dive computer, she thought, touching the sign. Just take your wrist unit off, hang it on one of the nails, then collect it on the way back up. No one checking later would be any the wiser that you’d gone deeper than fifty, and the surface unit didn’t generate a computerized dive record. It was the sort of trick Dad had pulled when he was alive. An extreme-sports diver, he’d do anything to push the limits, get to the depth he wanted to be.

She used her dive knife to make a cut in the netting, then carefully slipped off her dive computer and hooked it on to the sign. Switching on her torch she slid through into the enclosure, following the beam down into the darkness.

With her compass lubber line set hard against the north-west notch she began to swim down, down and down, following the lie of the rock, keeping about two metres from the bottom. Wellard paid out the lifeline behind her. The schematic was accurate – it was deep here. She went slowly, letting the torch guide her, doing sums in her head. No computer. She’d have to work out bottom times and decompression stops in her head.

A movement in the dark to her right. She whipped the torch towards it and stared into the beam, keeping herself steady in the water, letting herself float horizontally. There weren’t any fish in quarry number eight. It had been flooded for years now and the company hadn’t introduced any stock. No nearby rivers so there probably wouldn’t even be crayfish. And, anyway, that movement hadn’t been a fish. It had been too big.