Jeanne, unemployed and still living at home with her mother, lets herself be convinced by her new boyfriend, Franck, to move in with him at the electric appliance warehouse where he's the night security guard.
But Jeanne's dreams of a cozy life as a couple break down when Franck, who hid from her the true purpose of the warehouse's contents, is stabbed by a dealer and then arrested. On her way back to her mother's place, Jeanne is about to sink into depression when she gets a brilliant idea: she'll pretend she was the victim of a heinous crime that took place on the train. Incredulous, Louise asks an old friend, a well-known attorney, to help her daughter.