The Locked Room
Per Wahlöö
 The Locked Room has two plots running simultaneously. Larsson and Kollberg are extremely reluctantly part of a special task force that needs to solve a spree of bank robberies. Martin Beck is given a pity job after recovering from being shot at the conclusion of The Abominable Man; he needs to solve a classic situation of the genre: the locked room mystery. The incompetence of the Swedish police force has spread to the point that all three detectives are severely hindered in their work. One criminal walks free for a heinous crime he did commit, then gets to do hard time for a crime he did not.