Kind of calm. Kind of calm is something he can do. He managed to show up in this place without panicking too badly, so losing his voice should be less terrifying. Except somehow, it isn't.

Shit, he breathes, and rubs at his eyes. If Anna spots Bruce, he'll gladly follow. Meanwhile, he'll just close this box and consider the mittens the prime suspect. They're probably full of some kind of deadly voice-stealing mould, or something.