"Epitaph School is the biggest in the world," said the Headmaster proudly, rubbing his hands together. "Not even I know how big it is." Endill Swift is rudely plucked from his home at Gibbet Hall and carried by basket over a deep and murky ravine patrolled by a man-eating eel to this detestable establishment. In Nettles dormitory he dreams only of escape. Within the walls of this island fortress lurks a motley crew of teachers - Mr Fractor, Mr Litmus, Mr Jotter (no prizes for guessing what they teach) and Matron, who tours the corridors on a motorbike. Take a wrong turning and you might be lost for years. But the Headmaster takes the prize for the biggest crackpot of all. Endill and his friend Mould work secretly on their giant catapult. Surely, one day, escape must be possible?