Shipowner Marcel Lampson is about to go bankrupt. The luxury yacht 'Cross of the South', which lies on a canal near Paris, is the only ship he still owns. The situation has turned Lampson into a groundless drunkard who squanders his last money in the company of dubious types. Disgusted by the unrestrained activity on the yacht, Marie Thérèse, the shipowner's young wife, leaves the ship. Three days later, her body is found in an empty stable near lock 14. Commissioner Maigret is surprised when he sees the dead woman: The woman was strangled, but then bedded down as if the culprit had bid her farewell in reverence. On the other hand, a precious jewel necklace is missing... Based on the 4th Maigret novel Le Charretier de la Providence (1930/31), which appeared in German first as Die Nacht an der Schleuse, then as Der Schiffsfuhrmann, later as Maigret tappt im Dunkeln and finally as Maigret und der Treidler der "Providence".