Filled with many twists and turns, The Magus is the story of a young, egocentric, and not wholly likable Englishman who accepts a teaching job on a remote Greek island, where his friendship with the mysterious owner of an estate leads to a elaborate series of staged hallucinations, riddles, and psychological traps meant to test his concepts of love, freedom, being, and reality.

Here is what Eliot Fremont-Smith of the New York Times said of the novel in 1966:

"The Magus" is a stunner, magnificent in ambition, supple and gorgeous in execution. It fits no neat category; it is at once a pyrotechnical extravaganza, a wild, hilarious charade, a dynamo of suspense and horror, a profoundly serious probing into the nature of moral consciousness, a dizzying, electrifying chase through the labyrinth of the soul, an allegorical romance, a sophisticated account of modern love, a ghost story that will send shivers racing down the spine. Lush, compulsive, richly inventive, eerie, provocative, impossibly theatrical--it is, in spite of itself, convincing. It is, in fact, a trick ("magus" means magician or conjurer)--a trick about conviction. The stupefying thing is that Mr. Fowles has pulled it off. The book seems to have its own energy; it reverberates in the mind.