Cormac drew his shuriken. He sensed Aiden and Thorn at his back, and knew they were aiming their weapons. But there was no clear shot, and the creature dropped back down the shaft, holding on to the yelling Gant, his abseil-winder making a horrible penetrating shriek as the chain-cotton was wound out too fast. Cormac slapped his shuriken back into its holster.

‘Come on,’ he said.

They moved on down the shaft to where Cento lay against the wall. His fingers were driven into the rock of the wall, their fleshy covering stripped back from the metal underneath. His head and one arm had been ripped away, and synthetic flesh had been peeled from him to expose his gleaming metal interior. He was completely still. Cormac turned to Aiden.

‘Are you getting anything?’

‘His safe-storage is secure,’ said Aiden.

‘OK, take his place on the line and secure him here. We have to get after Gant.’ He turned to Carn. ‘You wait here till we call you. If we don’t, get the hell out of here.’

Cormac and Thorn went ahead into the settling CO2 vapour. Gant was still yelling, which must be a good sign. They jogged down the shaft, pulling against the friction setting as fast as they could. Meanwhile, Cormac punched in a particular attack program through the holster of his shuriken. It hummed contentedly as it drew full charge from the holster’s power supply.

‘We have to get it to release Gant,’ Cormac said over his shoulder to the grim-faced Thorn. ‘Once it’s done that, shuriken might be able to handle it.’

‘Gant said our weapons were bouncing off it,’ said Thorn.

‘Your light weapons . . . they bounced off the main body . . . but they damaged its legs and feelers . . .’

Just at that moment Gant’s yelling abruptly ceased, and his line went slack ahead of them. A cloud of CO2 vapour gusted up the shaft. Cormac knew what that meant; Gant’s coldsuit had been breached. It was probably his blood that was turning the carbon-dioxide ice to vapour. He guessed that Thorn probably knew this as well. Cormac continued on, carefully, as the line ahead of him was now only partially clad.

Soon they reached the area where the lights had been destroyed. Thorn shot two potassium flares past Cormac and the chamber below them was lit up with garish purple light.

‘It has no eyes,’ stated Thorn. ‘It uses sonar. You felt it?’

Cormac nodded agreement. He had felt it all right. ‘It destroyed the lights while they were moving. It was probably put here to destroy anything that moves.’ He glanced back to see Aiden coming up behind them fast.