The Paris Metro

Sunday May 16, 1937, 6:30pm. A young woman in a green dress and white hat is found stabbed on line 8 of the Paris metro. Laetitia Toureaux, the only passenger in a first class car collapses as the train pulls into the Porte Dorée station, a knife in the back of her neck... A real life "locked room" mystery, her killer was never found.