Alphonse and his wife Zulma hold the 421, a tavern in the outskirts of Lille, in the North of France. It is always full of regulars who play cards there and drink gin and exchange words in ch'timi, the local patois. But there has been trouble lately: felonies have been committed in the surroundings. So who can be those two strangers who have just rented a room each at the 421? Each sets about doing a bit of detective work.
In this romantic film inspired by Mädchen in Uniform, two young, independent Amsterdam women win a trip to the Ardennes in a writing contest. Unbeknownst to them, they are followed by an attractive journalist with a camera, after which they both fall in love with him, and they compete with each other for him.
Lieutenant Varnière, responsible for discovering the cause of the death of two officers in Algeria, unmasks the assassin in the person of a Russian who lives with three women. He falls in love with one of them and runs away with her while the Russian is killed by a devoted servant.
Set in Brussels, where Suzanne Beulemans, the daughter of a rich brewer is promised to marry Séraphin Meulemeester, the son of a rival brewer. The young man and his father both seem particularly motivated by the dowry of the young fiancée. But Séraphin has a rival in Albert Delpierre, a young Frenchman who is learning brewery from Ferdinand Beulemans and who is discreetly enamoured with the young woman. Albert learns Séraphin's secret that he is having an affair with a worker and that they have had a child. He promises Séraphin that he will never reveal any of it to Suzanne, but she is told by Isabelle, her maid.