Commissioner Maigret reappears much older and more difficult than ever to discover cancer is gnawing his life away.
He responds in an unexpected way by tapping a unique resource: the knowledge of medicine he continued to acquire throughout his career after leaving medical school and entering the police world. Maigret contemplates his fate in secret, which transforms him into a better man, but he becomes a dead man, too. It’s a matter of poisoning, in his own home, during his birthday celebration, surrounded by handpicked guests. Although several are angry with him, including two resentful colleagues, a jealous rival, and the writer who is fed up with his famous protagonist, there is no apparent murderer. Is it the perfect crime?

Everyone thought Jules Maigret was going to live forever. All of a sudden, the great detective’s dead. A premeditated poisoning is suspected. Who did it?