[@Gobby]
Shit I gotta stop rushing to get replies out, sorry for the triple post.

The exit arch is about six feet high, and about half that wide. Just enough for a human party to enter single file. The cavern ceiling, however, is more like anywhere from 10-14 feet depending on where you are and the stalactites etc. At least this close to the exit, since it's sloping down at the edge of the mountainside that the cave sits in.

Puck could stay in crevices and ledges, but to get through the exit he'll have to pass under the archway at some point, and the guards are aware of his presence so they'll be watching the air above them regularly.