Alyssa hovered on her broom making sure that none of the pixies escaped their surrounding circle. She made sure that she stayed out of the way of the other students and their wands because she had no intention of getting hit with anyone's freezing charm. There looked to be some overzealous younger students and she was worried for their safety too but figured that the Prefects would keep an eye on them.

She saw three pixies trying to make sneak through a gap in their 'human' circle. Alyssa quickly leaned forward on her broom and sped up to reach them before they could escape. As she flew towards them, she pointed her wand at them and aiming at them, said, "IMMOBULUS". A beam shot out from her wand and hit the trio point blank. They immediately froze where they were and stopped moving.