Dullandon Primary School runs strictly by the headmaster's timetable until the day a supply teacher, Miss Pandemonium, arrives. Within a week she has everyone trying to fly in home-made helicopters, making Friendship Cake which is far too friendly, and she even persuades the head, Mr Shrapnell, to cross the swimming pool in a leaky tin tub. Mr Shrapnell thinks it's all too much to put up with but, when the school inspector praises the school for its creative work, he comes round to her way of thinking.