There is no arguing, as Morgana runs out the door, the skeletons moving that much faster now that whatever is controlling them has now been noticed.

She pulls out her own might-be-a-screwdriver, which needs a cleaning from the crimson muck of earlier, ready to lock the door when the Doctor follows.

"Doctor, hurry!"

Underneath everything, the scraping of bones, the Doctor's footsteps, she hears something What is that noise she's hearing? It's an electronic beep, but what is it, and, more importantly, where is it coming from?