Colonel MacKenzie is traveling on a train with Lark Walters, the young and sheltered daughter of a wealthy friend of his. At a stop in a town, he sees a young man shoot another man in self-defense. Later, MacKenzie saves the same young man from being lynched, and brings him onto the train, where the overly romantic Lark falls for the young stranger. MacKenzie tries to keep them apart, but Lark won't give up. Meanwhile, other men on the train hatch up a scheme to kidnap Lark and hold her for ransom, and try to get the young man, Tate, to join with them. This episode introduces Tate as a series regular. (thetvdb.com)