10 Harry Potter Plot Twists You Never Saw Coming
6. Alastor Moody Is Barty Crouch Jr After A Few Drinks
Following the departure of Professor Lupin at the end of Harry's third year, we are three for three on disgraced and defeated Defence Against the Dark Arts teachers, and an unnerving pattern has begun to emerge.
Thus, suspicions abound regarding the nature of Goblet Of Fire's new professor: ex-auror and loosest of loose units, Alastor 'Mad Eye' Moody (Brendan Gleeson).
Mad Eye enters the series in a brief battle with the scorched sky of Hogwarts' Great Hall, and from there proceeds to teach students the Unforgiveable Curses, use transfiguration as a punishment, and aid Harry on his journey through the tough tasks of the Triwizard Tournament.
Whatever fate viewers had in mind for this unconventional but affable teacher, nobody could have guessed the truth sizzling beneath his gruff exterior: for the entirety of the school year, Mad Eye Moody has been the Death Eater Barty Crouch Jr (David Tennant) disguised with Polyjuice Potion.
Suddenly, every kooky, quirky action is cast in a different light, and we realise that Crouch was carefully leading Harry to his doom, ensuring no harm came to the boy along the way in order to invoke some blood-based juju and secure the Dark Lord's long-feared return.