Cate just nodded and smiled, not letting on it wasn’t her decision to bring him at all. She kind of liked that he thought it was.

When the Anomalocaris was within a few feet, the hovering creature lunged, its long appendages fully extending to wrap around the sea scorpion. The thick glass allowed no sound to penetrate to them, but all could imagine the crunching of the carapace that was taking place in the dark water. The Anomalocaris, scorpion now held tight in its spiked embrace, resumed its slow hovering as it carted away its meal to be dined on in peace in whatever lair it occupied.

“Holy shit,” Greg said. “That was intense.”

“The rule of tooth and claw.” Mironov turned and went back to his seat.

“Predator becomes prey.” Jack ran hands up through his hair. “Let’s take her forward Mr Gryzlov; five knots.”

“Did you see those tooth-like things on its arms?” Abby asked. “Could that have been the thing that attacked our drone?”

Cate watched, transfixed, as the weird creature disappeared into the utter darkness of the subterranean sea. Abby’s voice only just registered. “What? No, no, different structure.” She could feel Jack’s eyes on her, and knew what he thought, but obviously decided to keep to himself.

“Good,” Abby said. “Because that thing freaks me out.”

“Shit!”

Jack’s yell was just as startling as the giant that loomed up out of the darkness. He twisted the wheel, hard, swerving Prusalka out of its way.

“Jesus… all stop.” He laughed nervously. “I should have expected that.” Jack exhaled loudly. “Fuck… sorry.”

The Prusalka slowed, then stopped, and Jack switched on the halogen lamps.

The forest of huge stalagmites rose from the sunken floor like giant Easter Island carvings. Things darted in and out of the waving plant life on their surfaces, and long spiny-limbed crustaceans clung to their crusted surfaces.

“Stalagmites… under water?” Greg scoffed.

“The only way they could form is if this cave had been dry once… or at least this section of it,” Abby said.

“They’re enormous.” Greg leaned over Jack. “I can’t even see where they begin.”

“This lake or sea will probably contain trillions of gallons of water, but it’s either just seepage from above, or this massive empty cave system was dry, and an earthquake ripped it open and allowed seawater to pour in, dragging all the sea life with it.”

“Or at some time, part of it drained,” Cate said. “Maybe leaking its contents to the outside world before it refilled and then was sealed again.”

“Makes sense,” Mironov added from behind them. “If this ocean world had at one time opened to allow these things in, then it stands to reason it can reopen to let them out… or has at some time in the long distant past.” He stroked his silver beard. “That might be why we see evolutionary remnants reappear that we thought were long extinct.”