For over two decades Superintendent Maigret has been stumped in his efforts to identify the operators of a gang conducting daring daylight smash-and-run jewelry store robberies. When the body of Corsican immigrant Manuel Palmari turns up slumped in his wheelchair in his apartment, a bullet through his neck, Maigret begins by interviewing the other residents of his apartment building. Within this interesting mix of characters, a secret buried since WW II comes to light, providing a crucial clue.