10 Harry Potter Plot Twists You Never Saw Coming

Harry Potter and the Prisoner Of Azkaban pulls a fast one on viewers by laying the obvious truth in front of us to see and - quite rightly - assumes we won't believe it.

Throughout the film, Hermione turns up suddenly and unexpectedly; there one moment and gone the next. Couple this with the regular mentions of her sizeable timetable, in which she takes classes that clash, and there's a recipe for something shifty that's more than the usual magical manifestations we're used to seeing.

Unfortunately, the mouthpiece for the suspicions surrounding Hermione's habits is one of the least reliable characters, Ron Weasley; someone neither the other characters nor the viewers trust much when it comes to conspiracy theories and home truths. As Harry himself says, "Honestly, Ron, how can somebody be in two places at once?"

But they can, with the aid of a Time-Turner. This magical device, given to her in secret by the Hogwarts bigwigs, allows Hermione to attend several classes at once by skipping back in time throughout the day. It also allows her to take Harry back several hours in the film's final act, saving Sirius Black and Buckbeak the hippogriff from certain death.

Thank Merlin for that.