"Well done, the both of you," says Dr. Kleiner to the two he doesn't know. "Shall I take that back?"

He's indicating the shotgun. Sonia and the others are already on the move, though, peering nervously through the tunnels and moving as fast as anyone can who's heavy-laden.

"Keep an eye out for the old stations," says one of the rebels. "We should be able to make a straight run for the evacuation area once we get to Grove."