"Doesn't matter," the Doctor said, firmly. "We can't go out there yet. If something that unpleasant comes out during the day, I don't want to imagine what could come out at night."

As if to emphasize his point, a five-foot-long centipede-like creature scurried past the entrance of the cave. It stopped to brush its antennae against the edge of the entrance, but then sped past, apparently having lost interest.

"If it isn't light in another few hours, we'll head out again."

He gently pulled himself from Jack's hands, and slipped off his suit jacket. He wadded it up and lifted Jack's head, to put it under as a pillow.

"You've still got some rebuilding to do, I imagine," he said.