Commissar Maigret is called to the lock at Le Coudray, where a barge, the Astrolabe, cut loose, has drifted. On the board there were three dead bodies: an old Alsacian dog, Claessens, the skipper, Arthur Aerts, hanged with his dog's chain and his wife, Emma Aerts, hanged with a bedsheet. Everyone believes that the murderer is Emile Gradut, the stoker of the Aiglon VII, who was known as Emma's “boyfriend” and who had disappeared. Later, he was captured in the Forest of Rougeau, but he pretended he was innocent.
Maigret visits the bistro at La Citanguette, where the incident had taken place, then he decides to spend the night on board of the Astrolabe. During the night, he realizes that the reason of the murder was the money, as he knew that Emma had married Arthur for his reputed hoard of 100,000 francs. He digs through the concrete floor and finds the stash, truly 100,000 francs in gold coins. But, if the reason was robbery, why is the money still there and why was the barge cut loose. Also, if Emma wanted her husband's money, why was she dead? Or did Emile kill them both?
This report prepared by Dana Samson