In a small provincial town, the boarding-house is run by Mathilde Belin, the overindulging and over-demanding mother of Paul. When she is told by her envious sister Charlotte that her son is having a secret affair with Catherine, a salesgirl, she becomes furious and starts doing everything in her power to separate the lovebirds. Now Catherine gets pregnant and taking advantage of Peul's weakness, Mathilde puts pressure on Catherine so that she has an abortion.