In Paris, spring on the boulevards, well-dressed ladies everywhere. White hats are in fashion this season, Madame Maigret notes. But the commissioner is concerned with something else: “The bookbinder Frans Stevells burned a corpse in the oven of his house”—so it says in an anonymous note. The city’s best-known bibliophile, a clever and respectable man… and this? But the fact is undeniable: there are human remains in the oven. The bookbinder denies everything. There isn’t a single clue in the case. Nothing is known about the murdered person. Who will pull the investigation out of this dead end? A white-hat lady who appeared on the street by chance and disrupted the familiar routine of the Maigrets’ life…