Professor Severus Snape might be one of the Harry Potter franchise’s most complex characters, but he certainly isn’t very lovable.

Beloved wizard Dumbledore says Snape can be trusted. But why? Snape is a Slytherin, a master of dark arts and potions. He’s a bully, and he hates Harry Potter’s father, James. Most damning of all, he’s trusted by Lord Voldemort and his dark alliance.

But is Dumbledore ultimately wrong about Snape?

The truth is revealed in Harry Potter and the Deathly Hallows Part 2, the final installment in the magical film franchise, which opens Friday. Harry Potter author J.K. Rowling, actor Alan Rickman (who plays Snape) and Daniel Radcliffe (Harry Potter) shed light on the mystery of Snape’s true colors in this video from Warner Bros. Pictures.