Deanna Durbin offered her fans a change of pace in this mystery story seasoned with elements of comedy and music. Nikki Collins (Durbin) is a small-town girl visiting New York City to meet with Mr. Haskell (Edward Everett Horton), her family's attorney. As her train pulls into the station, she looks out her window into a nearby office building. She's shocked by what she sees -- a man is being strangled to death, and while she can't see the face of the killer, she gets a good look at the victim. Terrified, Nikki immediately goes to the police, but they think that her story is simply the product of an overactive imagination and send her on her way. Nikki, however, is certain that she witnessed a murder, and she approaches mystery writer Wayne Morgan (David Bruce) to help her piece together the facts of what happened. Thanks to a newsreel, Nikki is able to recognize the victim as Mr. Waring, a wealthy man who made his fortune in shipping; she attempts to contact Waring's family, but they're convinced that Nikki is a nightclub singer with whom the tycoon was having an affair. Hoping to contact the chanteuse in question, Nikki visits the club where she works, only to discover that she's also been murdered. Nikki soon finds herself being trailed by both Jonathan (Ralph Bellamy) and Arnold (Dan Duryea), two members of Waring's family whom she believes may have been involved in the crime, and could be trying to silence her once and for all. Like most of Durbin's vehicles, Lady on a Train's plot stops every now and then to give her the opportunity to sing a song; Western fans may want to keep an eye peeled for future cowboy star Lash LaRue, who has a small role as a waiter.
