It is the story of a singular adventure reached a boater of the Seine on his way home, after dining with a friend. He stops to smoke a pipe when trembles because of a strange movement in his sailboat that makes the wobble as the middle of a storm.
He decides to pull his anchor and go, but something in the bottom of the river prevents it. Hidden by a thick fog and suffers a sharp blow made him soubreter and it feels strangely agitated again. A horrible discomfort, then a shudder of horror the fact moan of fear, ever growing, becoming a real terror. He shouts for help unnecessarily.
To give himself courage he drinks rum and still stay long in the boat. When he can finally stand up, the fog disappeared and an extraordinary spectacle of nature calms him. Still shivering while he awaits the arrival of two fishermen who stir her anchor in charge of considerable weight: the falls aboard the corpse of an old woman with neck a big stone.