The story reflects the perspective of Nicholas Urfe, a young Oxford graduate and aspiring poet. After graduation, he briefly works as a teacher at a small school, but becomes bored and decides to leave England. While looking for another job, Nicholas takes up with Alison Kelly, an Australian girl met at a party in London. He still accepts a post teaching English at the Lord Byron School on the Greek island of Phraxos. After beginning his new post, he becomes bored, depressed, disillusioned, and overwhelmed by the Mediterranean island; Nicholas struggles with loneliness and contemplates suicide. While habitually wandering around the island, he stumbles upon an estate and soon meets its owner, a wealthy Greek recluse Maurice Conchis. They develop a sort of a friendship, and Conchis slowly reveals that he may have collaborated with the Nazis during World War II.
Nicholas is gradually drawn into Conchis's psychological games, his paradoxical views on life, his mysterious persona, and his eccentric masques. At first, Nicholas takes these posturings of Conchis, what the novel terms the "godgame," to be a joke, but they grow more elaborate and intense. Nicholas loses his ability to determine what is real and what is artifice. Against his will and knowledge, he becomes a performer in the godgame. Eventually, Nicholas realises that the re-enactments of the Nazi occupation, the absurd playlets after de Sade, and the obscene parodies of Greek myths are not about Conchis' life, but his own.