In the Le Mans railway station, Oscar Ribouis is waiting for the connection that will lead him to Rennes, his home town. Feeling a bit thirsty, he decides to have a quick one at the refreshing room. And feeling a bit lonely he invites a rail worker to have a drink in his company and tells him about his stay in Paris. But after a couple of glasses of wine, Oscar misses his connection. Worse, he goes out, walks on the tracks and what does he do but get his foot stuck in switches! About to be run over by a train he is saved at the last moment by his new companion, the railway-man. Saved from the train alright but not from a heap of coal he falls into! Now blacker than an African Negro, Oscar, once again helped by his companion, manages to get on a night train for Rennes. But, still drunk like a fish, he wakes all the passengers of the sleeping car and scares them stiff: they all believe they are being attacked by a black bandit! Opting for their lives rather than their money, the "victims" relieve themselves of their jewels and hand them over to the "Negro", unaware of what is actually going on. The following morning, Oscar is back home in Rennes, welcomed by his wife and two kids. In the meantime, Zambah, a poor Black man has been arrested for the sleeping car robbery. When Oscar reads the news in the paper and soon after discovers a necklace in his pocket, he realizes that this is a miscarriage of justice and goes to the police station to clarify the situation, Moulinet, the examining judge in charge of the case, has him sent to the same cell as Zambah.