The Laughing Policeman

On a cold and rainy Stockholm night, nine bus riders are gunned down by an unknown assassin. The press, anxious for an explanation for the seemingly random crime, quickly dubs him a madman. But Martin Beck of the Homicide Squad suspects otherwise: this apparently motiveless killer has managed to target one of Becks best detectives and he, surely, would not have been riding that lethal bus without a reason.