* Nicholas Urfe – The main protagonist, 25-year-old Englishman who goes to Greece to teach English and one day stumbles upon the waiting room. * Alison Kelly – Nicholas's girlfriend whom he abandons to go to Greece. * Maurice Conchis – Wealthy intellectual who is a main player in the masques. * Lily de Seitas – Young woman who is involved in the masques and with whom Nicholas falls in love.
* Joe – young black man, involved in the masques.
* Maria – Conchis's maid.
* Demetriades – Fellow teacher at the school.
* Lily de Seitas (older) – Lily's mother.
* Rose de Seitas – Lily's identical twin sister
* Benji de Seitas – the older Lily de Seitas's young son. * Kemp – Unmarried woman who rents Nicholas a room in London. * Jojo – Young girl whom Nicholas pays to accompany him.
The Magus is told from the point of view of Nicholas Urfe, who is bored with life. Having attended Oxford and taught for a year at a public school, he decides to take a position as the English teacher at the Lord Bryon School in Greece, on the island of Phraxos. Nicholas looks up a former teacher there, and is warned to "Beware of the waiting-room," without explanation. Nicholas is not deterred, but during the last few weeks before he leaves, he meets Alison Kelly, an Australian girl who is about to begin training as an airline stewardess. They are both sophisticated about sex and somewhat cynical, but each experiences some regret as they go their separate ways. During his first six months on Phraxos, Nicholas finds the school claustrophobic but the island beautiful. He realizes that he cannot write good poetry and that he is having difficulty forgetting Alison. In a funk, he visits a brothel in Athens and contracts a venereal disease. He seriously contemplates suicide. The first of the novel's three parts ends at this point. The mysteries begin as Nicholas goes swimming and someone leaves a book of poems, evidently meant for him to find. As he looks in the woods nearby, he finds a gate to a villa with a nearby sign Salle D'Attente, French for "waiting room." One of his colleagues at the school explains that the villa is owned by a rich recluse named Maurice Conchis. Nicholas decides to look him up and finds, inexplicably, that he is expected. After some conversation, as Nicholas is leaving, he finds an old-fashioned glove on the path and surmises that someone has been watching them. Invited back for the next weekend, Nicholas is astonished by Conchis' collection of art and by his claim to be psychic. After dinner, Conchis tells Nicholas about an episode in his boyhood when he was fifteen and met a fourteen-year-old girl named Lily Montgomery, whose image haunted him afterward. They were both musically inclined and fell in love, but in 1914, she led him to feel that he ought to volunteer for the army. Conchis explains that he deserted at the battle of Neuve Chapelle, and offers Nicholas a chance to gamble with his own life by rolling a die and promising that he will take a cyanide pill if the die comes up six. It does, but Nicholas refuses to take the pill; Conchis seems to approve his decision, and reveals that the die was loaded against the roller--as was World War I against the soldiers. That night, as Nicholas is going to sleep, he hears voices singing a war song and smells a foul stench. The next day Conchis encourages Nicholas to read a pamphlet by Robert Foulkes, written as he was waiting to be hanged in 1677. Nicholas takes it with him on a walk, falls asleep, and awakes to see a man in 17th-century dress staring at him from across a ravine. The man disappears before Nicholas can reach him. At dinner that night, Conchis tells of his wartime pretense to be on leave so that he could return to England to visit Lily. As Nicholas retires, he hears a harpsichord accompanied by a recorder, and investigates, to find Conchis and a beautiful girl dressed in Edwardian clothes, but he...