Harry and the other students meet Alastor "Mad-Eye" Moody in the fourth Harry Potter installment, The Goblet of Fire. He's the newest Hogwarts Defense Against the Dark Arts professor, a rough and aggressive man hiding a big secret.
After the Triwizard Tournament, Dumbledore, Snape, and McGonagall figure out that he's Barty Crouch, Jr. in disguise, a sadistic and clever Death Eater on a mission to bring Voldemort back to life. On a rewatch, fans may start picking up clues that Mad-Eye was actually Crouch, Jr. all along.
9 Professors Never Encourage Students To Cast Illegal Curses
During Mad-Eye's DADA lesson, he teaches the students about the three unforgivable curses: Imperius, Cruciatus, and Avada Kedavra. These curses could land anyone who uses them in Azkaban, and yet Mad-Eye encourages the students to perform these curses on bugs, even though it's illegal.
Upon a rewatch, this is an obvious sign that the professor is a Death Eater in disguise. A good or moral professor would never encourage students to perform spells that could hurt or kill others, and it's obvious Crouch is attempting to put darkness into the students before Voldemort's rise.
8 He Purposefully Picks Neville To Witness The Cruciatus Curse
Barty Crouch, Jr. was part of a group of Death Eater's, led by Bellatrix Lestrange, who tortured Neville's parents with the Cruciatus curse. Sadly, even after years of magical therapy, Frank and Alice Longbottom never recovered, and afterward, they were unable to recognize their son. This landed the pair in St. Mungo's Hospital as permanent residents.
Mad-Eye hand-picks Neville to watch as he tortures a bug with the Cruciatus curse, and of course, this traumatizes Neville. Crouch obviously knew what he was doing when he forced Neville into this position. This was Crouch's way of torturing Neville. It was more subtle than what he did to the older Longbottoms but no less terrible.
7 It's Immoral To Punish A Student With Transfiguration
Draco Malfoy frequently bullies and butts heads with Harry and his friends, so it's no surprise they fight over Harry's success in the Triwizard Tournament. Draco attempts to curse Harry, but Mad-Eye steps in and transfigures the boy into a small, white ferret.
Mad-Eye then bounces Ferret Draco through the air and into Crabbe's pants. It's immoral and inappropriate for anyone, much less a professor, to transfigure a student as a punishment, even if it’s Malfoy. Mad-Eye even admits to knowing it's against the rules. Any well-respected teacher would never punish a student so combatively.
6 He Admits To Knowing Lucius Malfoy
McGonagall turns Draco back into a human, and he threatens to tell his father about the incident. The professor then states that he can recount vile and evil tales about Lucius that will "curl [Draco's] greasy hair." However, the real Moody doesn't have reason to know the older Malfoy's stories.
On the other hand, Crouch does, as he and Lucius are both Death Eaters. He's bound to hear Malfoy's most sinister stories, as he's been one of Voldemort's most dangerous followers since the beginning. Whether conscious or not, the imposter briefly hints at his true identity.
5 A Screaming Voice In A Chest Isn't A Good Sign
Harry hears a voice screaming inside a locked chest when he visits Moody's office following the ferret incident. Moody plays it off, saying he won't bother telling Harry what's in the bin because he wouldn't believe it regardless.
A human-sounding scream in a locked box is never a good sign, no matter who the chest's owner is. Harry initially thinks the strange situation is just Moody's quirkiness, but it later turns out to be something much more sinister – the real Moody, held hostage for months.
4 Snape Discovers Missing Potion Ingredients
Severus Snape, Hogwarts' Potions professor, confronts Harry about missing Polyjuice Potion ingredients. As the professors know, Harry and his friends have brewed the shape-shifting potion illegally in the past, so it's not an unreasonable accusation. However, the kids aren't the culprits this time.
Polyjuice Potion is one of the most powerful potions in the wizarding world that makes the user look identical to another. Moody drinks from a flask on multiple occasions, and although initially thought to be alcohol, it's actually the potion. Eagle-eyed viewers can even see his face transform after taking a swig from his container.
3 Mad-Eye Is The Last Person Seen With A Dead Man
Mad-Eye confronts Barty Crouch, Sr., Head of the Department of Magical Law Enforcement, as he talks with Harry. Moody warns Crouch not to invite Harry to a summer internship at the Ministry of Magic, as the last boy to enter the Department of Mysteries never returned.
Crouch notices Moody's tongue flick out exactly as his son's used to, and the imposter knows his cover is gone. Later that night, Harry stumbles upon Barty Crouch, Sr.'s dead body in the woods. Mad-Eye, the last person seen with the victim, kills him to preserve his secret.
2 The Real Mad-Eye Transports Crouch To Azkaban
In Dumbledore's Pensieve, Harry enters the memory of a Death Eater's trial. The defendant is Igor Karkaroff, providing information on Voldemort's followers to get a lighter sentence. In a bombshell revelation, he claims that the Head of the Department of Magical Law Enforcement's son is a loyal Death Eater.
Crouch, Jr. flees in an attempt to escape punishment, but Mad-Eye Moody stuns him. The spell allows wizards to capture and ship him off for punishment. This could be another reason Crouch uses Moody to exact his revenge and further his plan.
1 He Secretly Points Harry Toward The Cup
Moody places the Tournament Cup in the maze's center to avoid a conflict of interest for the headmasters. As Harry lines up, Moody secretly points to the left, indicating the direction the boy can find the cup. While an ordinary Hogwarts professor is bound to root for their Champion, they don't condone cheating.
No morally-sound professor jeopardizes a competition by directing a student, and there's no real reason for Moody to help. He guides Harry through each round, ensuring the boy makes it to the cup, and the real Moody has no motivation to cheat for a student he has no strong connection to. It turns out his kindness isn't genuine.