In The Locked Room, Martin Beck, recovering from being shot, investigates the death of a man, who has been found shot in a locked room with no gun. Meanwhile, some of his former colleagues, now serving on a special task force, are trying to deal with an epidemic of bank robberies. The latter is a comedy of errors, with the police consistently messing up.
The authors are severely critical of the growth of Swedish police powers in the decade before this book was written. They also write harshly of the fraying of the social compact in the Swedish welfare system, which leaves the poor elderly to die alone, surviving on cat food. Only Beck comes off well in this book.