The Laughing Policeman

On a dismal rainy night in November, while Stockholm police are battling a mob of anti-war protesters, nine people are brutally murdered in a double-decker bus. The clues suggest a motiveless crime of violence. But the unexplained presence on the bus of Officer Ake Stenstrom, friend and colleague of Superintendent Martin Beck of the Stockholm Homicide Squad, points to more complicated motives of revenge or concealment.