Jack nods with returning enthusiasm*, then lifts his head and listens. There's no whaley wails yet. Not a hint of the ground trembling. But he knows from experience that it won't be long until they run into something.

Okay, hang on, he wants to test his gun now. He pulls it from his belt, kind of pokes around it for a bit -- it's still damp but the bullets seem fine -- and then cocks it and lines up... lines up... liiines uuuup. . .

BLAM!

Jack lets out a "ha!" of triumph as the revolver does its job splendidly, taking out a wall light a whole floor up. Okay, now they can go.

With a jerk of his head, a mute 'follow me', he picks a direction and starts to head out.

*once he realises that this is a metaphor