Two men are participating in a duel on a sand dune off of Mississippi. One man is a tall and older gentleman named Captain Noddy, and the other is a younger man who had said something that offended Noddy. A man named Myron is watching the duel, and there is a man next to him watching whom he has never seen before. Noddy kills the younger man, and Myron explains to the stranger that this is the twelfth young man that Noddy has killed in a duel.
The two men go to a gambling den together to get drinks. The stranger says his name is Darius LeClair, and that he is from Mobile, and is a gambler. The men talk about Noddy and how he is a formidable opponent, when all of the sudden Noddy and his entourage walk in. Darius buys the group drinks, but he and Noddy soon start bantering when Darius says the young men are not worthy opponents for him. Noddy challenges Darius to a duel.
Rumors spring up all around town that Darius is an experienced duelist from Europe. Myron goes to visit Darius in his hotel, and talks about the rumors. Darius shows Myron a set of expensive dueling pistols that he has, which convinces Myron he is an expert. Darius tells Myron to take both their money and place a bet on him in the duel.
That night, Darius attends a ball that Noddy is also invited to. As he watches the young women dance, Darius notes that he is not attracted to them, and is attracted to the men. Darius and Noddy confront each other, and Darius calls Noddy a murderer and a coward. Noddy lunges at Darius, but he is pulled away by his seconds. Noddy drinks heavily for the rest of the night.
The next day is the duel. Darius implies that Noddy's seconds tampered with his gun, and he offers to postpone the duel since Noddy is hungover. Noddy is furious, and insists that the duel continues, although Darius makes him switch guns. Noddy is nervous and shaking. Noddy shoots early, missing Darius and hitting a tree. He kneels on the ground begging Darius, who tells Noddy that one of the young men he killed was Darius's brother. Darius shoots to the side of Noddy, and says that he is condemning Noddy to life.
After the duel, Darius reveals to Myron that he has never set foot in Europe or used a weapon in his life. He payed the newspaper to write the story about him to make Noddy more nervous, in addition to emphasizing to Noddy that it was his unlucky thirteenth duel and that he may have only been successful in the past because of the guns being rigged, although they were not. Darius tells Myron that the young man Noddy killed was not in fact his brother, but a dear friend who was dear enough to risk it all.