Doctor: Don't run. Don't shout. Keep your voice down. Draw attention to yourself and the spell is broken. Just keep to the shadows.
Jack: Like ghosts.
Doctor: Yeah, that's what we are. Ghosts.
— "The Sound of Drums", Doctor Who
Keep this up, and I could leave you bleeding to death in this lobby. A sprinkle of sand, and your body will sit here and rot. Your friends will hold their noses and step over your corpse, but you’ll remain here until the animals take you to pieces.