Bella doesn't have another class with Feral until Magical Defense, so she runs off to find him while lunch is still ongoing.

"Sherlock warned me about what's in Defense today. It's these things called boggarts that turn into your worst fear when you look at them."

"...I should probably skip Defense," says Feral.

"I'm going to warn the teacher that mine might be a dementor and if boggarts are good at faking effects like theirs I should skip my turn. What's with yours?"

"Uh... when I get really scared, everything catches fire?" he says.

"That's true," allows Bella. "But like - the other thing I think mine could be is just myself dead and that would be unsettling but not scary, are you sure you'd get something that would scare you out of context?"

"Okay, okay," says Bella, "skip if you want, it's the terrible memory charm teacher, goodness knows I wish I were comfy skipping classes. I'll tell you how it went after."

"Great," he says. "See ya."

"He says boggarts can do the thing but he doesn't believe I've seen a dementor," Bella says desperately, "and he wants me to go in front of the boggart anyway."

"...Fuck," says Feral. "And I'm supposed to what, back you up?"

"If you don't I have to skip and I don't want him to flunk me. He saw me, he knows I'm not sick, and he already doesn't like me from the memory charm incident since Mrs. Stark didn't get him fired."

"Okay," sighs Feral, "I'm game."

"I'm sorry," says Bella apologetically, and she heads back to Defense with him.

Feral follows. He's pretty sure that him setting a bunch of things on fire would do less damage than a Dementor showing up in the middle of the classroom, so he doesn't hang back when they get there.

"I did meet a Dementor over the summer and Feral can confirm," Bella says, "and the boggart might well turn into one if you throw it at me and you can't do that to a whole room full of people."

The teacher looks skeptically at Feral. "Were you even planning to show up? Miss Swan should not have had to fetch you."

"I wasn't, actually," he says. "I have this problem where when I get scared things catch fire."

"You use that excuse to get out of a considerable amount of work," snaps the teacher, "but you've had more than enough time to grow out of infantile accidental magic. If you do the exercise correctly you will experience scarcely a second of actual fear - the incantation is Ridikkulus, you must think of a way to render your fear humorous, and if Miss Swan cannot then she at least has the history of classwork to conceivably make up for it. You on the other hand -" He flicks his wand, and Feral scoots forward in front of a cupboard, and the cupboard opens.

The teacher puts out the fire with a slice of his wand, expression unreadable.

"Feral," warns Bella in his ear, putting a hand on his elbow.