Lady on a Train

Deanna Durbin stars as Nikki Collins, a debutante who witnesses a murder in a nearby building from her train window. When she reports the crime to the police, they dismiss her story, so she turns to popular mystery writer Wayne Morgan (David Bruce) for help. As she enlists his aid, she attracts the attentions of suitors and killers, including Margo Martin's fiancé Jonathan Waring (Ralph Bellamy), who is hiding a dark secret.