A Darker Form of Magic, book three: Dementors

Things change after Harry takes in the magic of the basilisk, but that doesn't mean that the world waits for Harry to catch up as a fugitive roams the streets hunting for a rat, a werewolf stalks the halls hoping for a second chance, and summer plans go awry. Harry just wants to survive the year after the hell that was second year, but between teenage emotions and the mass murder after him, he almost begins to wonders if he will.

It doesn't help that dementors are haunting the school.