[he immediately stops tapping when the metal sounds do so much better to reverberate through even his own body in this crevice]

With any luck, there'll be a pinch and it'll get stuck.

[he'd turn his head to give her the impression of looking at her incredulously if he could.]

That's a ridiculous statement and you know it. It seems like the footing is heading up. Could be rubble from a second floor. We may be able to gain some real distance from this thing.