What happens in science class during the lecture on wolves?

Mia asks the teacher about foxes to upset Lissa and to get the other students talking about it. This upsets both Rose and Lissa, but not as much as when a boy suggests that maybe Lissa killed the fox herself. Rose defends Lissa, of course, and they get into an argument. To break it up and defend Lissa, whom he really likes, Christian sets the boy's clothes on fire, then quickly puts the fire out before it can hurt the boy.