Dementors Attack the Trio in Hogsmeade
Pages 555-557
Death Eaters release Dementors to find Harry, Ron, and Hermione, but Lord Voldemort has instructed them not to kill Harry, only capture him. The Dementors' presence causes the temperature to drop as Harry casts his Patronus to drive them away. His silver stag Patronus gives away their position, but they are saved when a mysterious figure calls them into a nearby building.
