" There was some kind of X-men emergency, so all the teachers were gone. This happens every now and then. It's one of the perks of having super heroes for your teachers - when the world is about to end (which is like at least twice a month), school gets canceled. Heck, three weeks ago there was a big chemistry final for the upperclassmen. Beast was the teacher - he's this big, burly guy who can do acrobatic stuff like a monkey, but he also happens to be a super-genius. He's, like, legendary for his tough finals, so there were kids walking through the halls, going, "Oh, God, please let Galactus try to eat the earth. Please please please let there be an alien invasion by the Skrulls! "

― Barry Lyga , Wolverine: Worst Day Ever