Inspector Stuart Stranaghan investigates the attempted murder of the headmaster of a prestigious boarding school two years after the unsolved murder of his predecessor. Stranaghan has been chosen because of his literary background, which, it is felt, makes him better placed to deal with the motley collection of academics that make up the list of suspects. Stranaghan is not the standard fictional sleuth; he is intelligent certainly, but he is no mastermind in the mould of a Poirot or a Morse. The investigation plunges him into waters populated by intellectuals and ideas not encountered in routine cases. Stranaghan's interest in this world, for so long repressed by his dealings with the grubby end of the human spectrum, is suddenly reawakened. The hub of his fascination is the German teacher, Dr Greenfield, a charismatic figure who runs the Thinkers' Club and exerts great influence on the minds of his more gifted pupils. The relationship between the two men comes to form one of the central pillars of the story and sets the tone for the unconventional outcome.