Private detective Gerhard Self, 68, is hired by his old school friend Korten - now the head of Rhineland Chemical Works - because somebody is sabotaging the company's computer system with pranks such as ordering 100,000 rhesus monkeys for the research department. The culprit also mixes up tennis court bookings so that 108 players turned up on the same day. After Self is hired there's a gas explosion at the company compound. He's hurt, and wonders if the case is more sinister than it first appeared. The over-complicated plot is narrated with smug, deadpan humour. Self throws jibes at corporate culture and computer technology. As the mystery unravels and the writing becomes more serious, Self is forced to face up to his past as a Nazi prosecutor. He suffers a breakdown and complex moral questions are raised.