This one is actually quite annoying, Hermione is stuck in the girls room with an escaped troll trying to kill her. You will dodge the attacks of the troll by ducking, jumping, and strafing left and right which is very easy once you understand the movements of the troll. Next you will throw blocks of wood at the troll, stick your wand up the trolls nose, and finally use the spell Wingardium Leviosa to drop the trolls own club on its head. Do well in each of those to achieve the five stars. This may take a little bit to get the hang of each one but just keep at it. The Wingardium Leviosa part is the worst one in my opinion, just cast it on the club and try to get it on your first cast, anything more will probably mess you up big time. This is also during year one and will be your third minigame.