"But I don't think you'll be able to keep pace the entire distance, and we're running out of time. We'll have to risk using this. Get on." Cainen gratefully climbed into the passenger area, which was roomy, built as it was for two Enesha. Aten Randt eased the little engine to its full speed—about twice an Eneshan's sprinting pace, which seemed uncomfortably fast in the cramped tunnel—and then turned around and raised his weapon again, scanning the tunnel behind them for targets.

"What happens to me if the base is overrun?" Cainen asked.

"You'll be safe in the living module," Aten Randt said.

"Yes, but if the base is overrun, who will come to get me?" Cainen asked. "I can't stay in that module forever, and I won't know how to get back out. No matter how well-prepared this module of yours is, it will eventually run out of supplies. Not to mention air."

"The module has the ability to extract dissolved oxygen from the water," Aten Randt said. "You won't suffocate."

"Wonderful. But that still leaves starvation," said Cainen.

"The lake has an outlet—" Aten Randt began, and that was as far as he got before the engine derailed with a sudden jerk. The roar of the collapsing tunnel drowned out all other noise; Cainen and Aten Randt found themselves briefly airborne as they were hurled from the passenger area of the rail engine into the sudden, dusty darkness.

Cainen found himself being prodded awake an indeterminate time later by Aten Randt. "Wake up, Administrator," Aten Randt said.

"I can't see anything," Cainen said. Aten Randt responded by shining a beam from the lamp attached to his weapon. "Thanks," Cainen said.

"Are you all right?" Aten Randt asked.

"I'm fine," Cainen said. "If at all possible I'd like to get through the rest of the day without hitting the ground again." Aten Randt clicked in assent and swept his beam away, to look at the rock falls that had them closed in. Cainen started to get up, slipping a bit on the rubble.