The novel works as a strange Bildungsroman, in which the main character, Ian Wharton, learns the art of black magic from Broadhurst, who is also known as the Fat Controller.

At the Fat Controller's behest Ian engages in a series of strange acts including time travel and trips to an alternate reality called the Land of Children's jokes, a grotesque alternate universe inhabited by the menacing and deformed characters from jokes.

The protagonist's education culminates in bizarre rites of bestiality and necrophilia.

However, he finds that in exchange for knowledge of the black arts Broadhurst begins to take over more and more aspects of his life.

Nicholas Lezard said of the book that "No one else I can think of writes about contemporary Britain with such elan, energy and witty intelligence.