This is the best and the most cynical novel in the Martin Beck series so far. Returning to work after an injury, Martin Beck is given a strange case to investigate. Meanwhile his colleagues Gunvald Larsson and Lennart Kollberg have been assigned to a special task force to deal with a series of bank robberies plaguing Stockholm.
Both cases are hampered by the continuing decline of the police force. New recruits are increasingly incompetent and public respect for the force has plummeted. If it's not ineptitude that hampers their investigations, it's bureaucracy and politics.
Sjowall and Wahloo contrast this recognisably real world scenario with a classic detective fiction construct, the locked room mystery. Martin Beck has to solve the case of a man found shot dead in his apartment, with the door and window locked and no sign of a gun. Unlike most classic detectives, Martin Beck has to confront the possibility that the gun may have been taken from the room while it was supposed to have been guarded.
I was looking forward to finding out how Sjowall and Wahloo dealt with the locked room idea but that plot turns out to be the least satisfying part of the book. The allusions to Martin Beck living in his own 'locked room' are a little overdone and the way he solves the mystery is somewhat cliched.
It's the Larsson and Kollberg plot that is most enjoyable. They participate in a bungled apartment raid that goes wrong in such ludicrous fashion that it's hard not to laugh and their meticulously planned attempt to foil a major bank robbery goes wrong in an unimaginable way. But it's the way their case ends that really makes the book worth reading.