“Well, there are enormous cave systems all around the world that are fantastically old even by geological standards. There’s the Ursa Minor in the Sequoia National Park, St. Michaels in Gibraltar, or the Jenolan Caves in Australia that are supposed to be nearly four-hundred million years old. But this could easily top all of those.”

“It’s warm, and feels like jungle humidity. There must be geothermic activity keeping this underground water body in solution even though it’s buried under the coldest continent on earth. Or perhaps the heat from the earth’s interior is keeping the sea from freezing—a form of geothermal heat radiating up from below and warming rocks on the underground seabed.” Silex was wringing his hands and seemed to be talking to himself. He licked his lips constantly now, and they had become chapped and cracked. He rambled on.

“Hmm, yes, I’d say the ice sheet above would also be acting as a blanket, protecting the lake from cold temperatures on the surface. The heat source probably gives it the basis for its food chain in the near dark. Similar biospheres occur close to deep vents miles under the ocean, you know.”

Alex was looking at Dr. Silex with concern. “Let’s get further up onto that beach and rest—I’m not happy being this close to the water. Tank, get me some readings.” Alex needed to keep them all moving and focused on getting to the surface. As soon as someone started to give up hope, a malaise—or worse—would set in.

Tank reached into his backpack for his small radar unit and fiddled with the buttons before pointing it at the ceiling and then turning it in a wide semi-circle. “OK, we’re just under three miles down; we have moved that much again from our initial insertion point.” Some more fiddling. “The body of water is . . . well, it must be over a hundred miles in length as it exceeds this device’s readings, and about fifty-five miles wide, depth unknown. There are . . . there are multiple movement signatures in the air above and below the water—varying sizes. Christ, some of them are huge—maybe whales, at least that big anyway.”

Alex looked at Aimee. She shrugged and narrowed her eyes—he knew what she was thinking; they still hadn’t come across the creature that attacked them and owned the rest of the tentacle they hacked off. God help them if that thing wasn’t top of the food chain. Meeting something that size in a cave was one thing; you had a wall at your back and it was defendable, to a degree. Out in the open they were just more food for the taking.

“Let’s move. Single file. Takeda, lead us out, please.”