10 Harry Potter Theories You Won't Be Able to Wrap Your Head Around

One theory speculates how Slytherins may have joined the rest of Hogwarts in the fight against Voldemort if one key detail changed in Harry Potter and the Goblet of Fire. A Tumblr user found a passage noting that Slytherin Cassius Warrington also cast his name in the Goblet of Fire. If he were chosen and followed the same path as Cedric did, Slytherins would've totally rejected Voldemort — as he would've killed Warrington, a pure blood.