Commissar Maigret investigates a series of bold robberies. The criminals choose victims who aren’t guarded—cashiers and bookkeepers transporting large sums of cash.
At the same time, in the forest of Boulogne, they discover the brutally mutilated body of a burglar long known to the commissar. It is this murder that draws Maigret in even more, and he takes the case on his own initiative, carrying out an unofficial investigation.