Heath is on a stagecoach with some other passengers when masked bandits chase them down and rob them. Forcing them to leave the coach, the leader of the bandits then kills the driver and polishes the gun used to kill him. Heath and the others are forced to walk to the nearest town in their stocking feet while the bandits ride off. It is only then that the bandits remove their masks, and the leader is a woman.
Planning to rob the Stockton bank, the woman - named Dilly Shanks - goes with one of her brothers to stake out the grounds. While in town, Dilly spies Heath, and gets into a poker game with him and two other men. She easily cleans them out, and then offers to buy Heath a drink. Heath declines, but expresses a wish for another time perhaps. After he leaves, Dilly goes home to her gang of outlaw brothers and tells them that they'll wait longer to rob the bank until the cattlemen come to Stockton with their savings the following week.
Meanwhile, Dilly approaches Heath while he's out working and feigns a minor injury to win his close attention. He sees through the stunt, and has to laugh at her spunk. She expresses her interest in him, and he is surprised by her forwardness. However, she does not perceive that her pursuing him is actually pushing him away.
The next day in town, Dilly spies Audra talking with Heath outside a boutique. Not knowing she's his sister, Dilly is jealous and threatens her to stay away. Audra does not tell her their relationship, but hides her amusement. The next morning at the breakfast table, the family ribs Heath about his new love interest, while he wishes to avoid the subject.
Dilly approaches Heath again, this time with an outrageously expensive saddle. Heath doesn't want to accept it, and tells Dilly that he likes to do the gift giving and the courting as the man. She still is oblivious to his lack of interest, and continues to push, this time talking him into dinner. Meanwhile, back at her house, Dilly explains to her brothers that she has decided to get married and settle down. Helpless without her, they scheme to rid her of her new love interest.
Dilly pays a visit to the house and ends up chatting with a surprised Victoria, who has been warned by Heath that this girl is as "quiet as a rebel yell." The visit ends with an angry Dilly threatening Victoria, mistakenly believing that Victoria's cautions are snobbery because of her status.
As Heath is traveling alone, he is ambushed by Dilly's brothers. Dilly hears the raucous and comes to Heath's side, and her brothers leave. As Heath watches Dilly polish her gun, he is reminded of the ambushed stagecoach and murdered driver. He catches Dilly in a lie, and tells her that he could not marry such a woman. She protests this, but he leaves her. Stunned, she goes back to her brothers and threatens Heath's life. They scheme to use him as a hostage in the bank holdup.
After kidnapping and tying up Heath, Dilly's brother falls asleep while on guard duty and his cigar falls to the floor. Heath deftly snags it and manages to singe his ropes until he can wriggle free. Dilly has meanwhile been kissing him sensuously, and he captures her, takes her gun, and rides off to freedom.
Dilly decides to burn down the whole Barkley estate in revenge of being humiliated by Heath. While she is still torching the barn, Heath comes in and takes a bullet from her in the leg. Her brothers warn her off, but she returns to try to rescue him. In doing so, the spooked horses rush her and trample her. She dies in Heath's arms.
In the final scene, Victoria and Heath are talking, and Heath remarks that he never got around to returning Dilly's expensive saddle. He says that, while it's not his style, there's something about it that he likes. Victoria smiles at the implication to Dilly, and the two go for a ride.