The Moth (1934)

Wealthy young socialite Diane Wyman squanders her fortune and becomes involved in a scandalous raid at a wild party Her legal guardian a lecherous old man who has the hots for her hires a private detective to spy on her He tails her to a train headed for New Orleans but she catches on to him She befriends a young woman aboard the train and they both give the private eye the slip What Diane doesnt know however is that that her newfound friend is actually a notorious criminal known as The Moth and she has her own reasons for helping Diane escapeshe too is being tailed by a detective whos after a cache of jewels shes stolen