It's a screwdriver. Sonic.

[ he'll point it at Waver jokingly, giving waver a quick scan. ]

You're human, alright, but just a little different. Tell me, is everyone in this world like you? [ he steps outside, tilting his head at the professor. ] What's the fastest you can make an escape?

[ because The Doctor looks like he's .5 seconds from breaking into a sprint. ]