Retelling of "The Tempest" in which the Prospero-figure (Conchis) kidnaps a young English teacher (Nicholas) and psychologically tortures him for weeks (I think). Nicholas is a smug and unpleasant character, which makes you wonder if someone who tortures a nasty person is good or bad? When I was a kid I wondered if the Devil was good because he tortured bad people, and maybe JF had the same idea.
There is also a gripping tale of wartime atrocities in Greece that has been published as a standalone story and thereby hangs an issue with the book. Because outside this separate tale The Magus as a whole is absolute guff. It is full of pretentiousness and hints and allegations and black men in masks and alluring twins and a lot of Sadeian crap, but Sade was a rebel against the crapness of 1970s popular music, er, the French aristocracy and its corrupting power and Conchis, the Magus of the title, isn't. On and on and on and on it goes. JF even wrote a director's cut version which is even more tedious. Why oh why?