When she returned, Filius was right in the middle of explaining what they’d be doing for the rest of the month. "...and you will be grouped together in teams of four; two from each house, one boy and one girl. Your assignment is to design a roller coaster using charms instead of the muggle methods of operating the ride. The coaster should take the rider on no less than a twenty-second ride, and no more than a minute long. It must include at least one loop and one corkscrew. You are free to transfigure any materials you feel will help you accomplish your task. This assignment will be due at the end of the month."