A handwritten message delivered to Maigret at his Paris office prompts him to visit Saint-Fiacre, the place of his birth and childhood and home to the estate which his father managed. A crime, the message states, will occur during the first mass of All-Saints Day. Maigret and his wife make the trip and attend the mass. A death does occur. But what's the crime? How can an obvious natural death be murder in any sense of the word?
This is a very special story among the many Maigret mysteries written by George Simenon. We learn much of where and how Maigret was raised. References to and memories of the past are handled beautifully in this film. One difference between book and film is that Mrs. Maigret joins her husband in his visit to his "past" and it's a very good addition and one, frankly, that Simenon should have included in the book. Maigret's visit to the chateau of his youth, his encounter with those who knew him as a child, and his wandering about the estate provide moments of amusement, wistfulness, and poignancy. One doesn't read Simenon's Maigret mysteries to simply move to the denouement and find out "Who did it?" Such matters, yes, but only a bit. The best parts are the lingering moments in between. In this film, this is understood as it's those many lingering moments that make watching this episode worthwhile.
The conclusion seems a bit odd. A group of suspects are gathered round a dinner table. Conversation and accusations lead to the big reveal. It seems a bit forced but it is true to the book. This is what Simenon wrote and unlike some of these Maigret book-to-film episodes I don't see any other way the scriptwriters could have gone in finishing this one. I didn't find it a satisfying ending (though maybe you will), but I didn't care. The mystery of a death is not what makes this "mystery" the fascinating story that it is.