The liquid stealth with which the creature had pursued them so far was abandoned and replaced with a ground-shaking crashing like the charge of a hundred elephants. Matt and Monica looked at each other, then back to Alex, momentarily blinding him as they directed their torches into his face. Alex turned and closed his eyes for a second to get some night vision back, but when he opened them it became clear to him exactly what strategy the creature was going to use. A gigantic tentacle was moving quickly down the tunnel; as it came forward it knocked car-sized boulders out of the way like a child would do with its toy building blocks.

This was not the place for engaging the creature. Their armoured caving suits would either be snagged by the razor-sharp hooks on the tentacles or they would be crushed as the creature knocked a boulder on top of them. Alex fired a stream of compressed gas projectiles into the club tip, but he knew that this would only slow the advance.

“Ms. Jennings, find us some cover, double time. Everyone else follow her—now!” Alex was running and turning to fire every few seconds. He was aware they only had a few minutes before they were run down or crushed when he heard Monica call from just ahead.

“Careful under here . . . it’s a floating choke.”

Alex could see what she was referring to. The rift they were moving through was only about twenty feet wide, but suspended over a narrowing area was a table-shaped slab of stone of immense proportions that held tons of debris above it. Aimee had dropped back to Alex and looked at him with her determined, grime-streaked face.

“Are you thinking what I am?”

“Oh yeah, time to shut the door.”