When Lord Petrefact hires Walden Yapp, Professor of Demotic Historiography at Kloone University, to write a scurrilous family history Yapp finds plenty of material in Buscott village, where Frederick Petrefact is running the Mill and adding new vices to the family collection.

If Yapp can lay his hands on the Petrefact Papers in the Buscott Museum he may be able to expose the multi-national capitalism of the Petrefacts to the whole world. Unfortunately when he takes lodgings with the Coppetts of Rabbitry Road and encounters the peculiar charm of Rosie, a woman of large body and little mind, he sets in motion a train of events which are to lead to his undoing.