The night eight people were shot to death in a Stockholm bus, police detective Martin Beck seriously wondered what makes anyone want to be a cop. One of the dead was a colleague of Beck's, an ambitious young detective whose private life was both perverse and mysterious. There were no clues.
Working on a hunch, Beck and a team of experts set out on the largest manhunt Sweden has ever seen. Indiscreet revelations of the dead detective's girlfriend help Beck reconstruct the steps that led to his death. Then …