The classroom used by the Transfiguration Club had been enlarged by magic at some point.
Professor McGonagall was standing in the middle of the room, waving her wand to demonstrate various transfiguration spells to everyone, leaving all present dazzled.
She manipulated fire and controlled streams of water, shot dangerous clusters of lightning bolts from her wand, turned the floor into a swamp with churning mud that bound enemies or formed a barrier for self-defense to block incoming spells.
Chapter 59