- Harry finds Sirius unconscious near a pond.
- The water suddenly freezes over. Oh, is it a magic ice-skating pond? How fun.
- Oh wait. No. It's Dementors. The opposite of fun. They're going to suck the life out of Sirius' mouth.
- But a blinding Patronus from across the pond repels the Dementors.
- Who could that Patronus, which looks like a stag, belong to?