Gabrielle was so taken aback that for a second she just stood there while Susan rained blows on her head; she then recovered, seized the first thing that came to her hand - which happened to be a jugsaw puzzle with which one of the Removes proposed to amuse herself after supper - and hit Susan over the head with that. As the pieces fell round Susan like a miniature snow-storm, she reeled a bit, then went into the attack again and kept on banging Gabrielle over the head with Gail's book, which made the most satisfactory and resounding thuds. Gabrielle, retreating, put up her arms to cover her head, but Susan was still getting in some shrewd blows, amid yells of encouragement from the Removes who hadn't seen such a fight since they had left the kindergarten - when suddenly the door was flung open and a prefect called Avril Barrett strode into the room.
From SUSAN'S TRYING TERM, Chapter 6, More Trouble.