This is the third Maigret novel published by Simenon in his inaugural Maigret year of 1931. This book finds Jules Maigret, the Chief Inspector of the Paris Flying Squad Criminal Police, once again called out of Paris to investigate the strangling murder of a young woman found in a barn next to the canal that carries traffic south from Paris to Marseilles.  Among the barges and working boats, Maigret finds a yacht skippered by a British peer, Sir Walter Lampson, a retired colonel from the British army in India.  It is his wife who has been murdered and before long, his young companion Willy, a fancy dresser with a police record, is also found strangled in the canal.  Maigret has many suspects but finally settles on an old horse handler from one of the barges, the Providence.  Maigret discovers that Jean has a prison record that relates to a murder he committed in order to gain a bequest for his wife, who turns out to be the murdered woman, now wife of Lampson.  The strength of this book is its creation of the world of canals, barges, and those who work them while also providing an early example of Maigret’s approach to crimes, i.e. immersion in the environment while learning about the psychology and lives of the victim and the suspects.