Le crime de Monsieur Lange

A man and a woman arrive in a cafe-hotel near the Belgian frontier. The customers recognize the man from the police description. His name is Amedee Lange, and he murdered Batala in Paris. His ladyfriend Valentine tells the whole story: Lange was an employee in Batala's little printing works. Batala was a real bastard, swindling everyone, seducing female workers of Valentine's laundry - One day, he fled to avoid facing his creditors, and the workers set up a cooperative to go on working. But the plot is less important that the description of the atmosphere just before the Popular Front.