In the border town of Grivet, the young French woman Germaine is killed. Maigret, called from Paris, finds out that the girl was a close friend of Joseph Peeters, the son of a merchant. The investigation of the Peeters family leads to interesting facts. Daughter Anna is the strict leader of the family. She has determined that the unstable Joseph will become a lawyer and has already chosen a girl to marry her brother. The barge owner Cassin, who is not averse to alcohol, severely incriminates the Peeters family with his statement ... Based on the 14th Maigret novel Chez les Flamands, written in 1932, published in German under the title Maigret bei den Flamen.