The story opens with Breckinridge Elkins reflecting on his reputation among buffalo hunters, who view him as a greater threat than hostile Comanches or the U.S. Cavalry. The tale then flashes back to explain why.

Breckinridge is traveling through New Mexico, broke after a political altercation in Albuquerque ends in violence. He receives a letter from his friend Glaze Bannack, who’s jailed in Panther Springs for injuring a deputy with a “piece of scrap iron.” Glaze asks Breckinridge to collect $10 owed to him by Old Man Garnett and bail him out. Breckinridge does so—though not without a violent scuffle, during which Garnett bites him and shoots at him with a buffalo rifle.

On the way to Panther Springs, Breckinridge sees a beautiful young woman named Judith Granger. After intimidating her suitor, Curly Jacobs, Breckinridge resolves to court her himself. He buys a too-small shirt with Glaze’s money and heads to the jail, only to inform Glaze that he spent part of the money on clothes and must now gamble to earn the rest.

At the Golden Steer saloon, Breckinridge exposes a card cheat (Jabez Granger, though he doesn’t yet know it’s Judith’s uncle), starts a fight, and ends up threatening both the sheriff and the justice of the peace. Terrified of his reputation, they let him go.

Breckinridge dines with Judith and her formidable Aunt Henrietta, who takes an instant liking to him. Judith, warming to Breckinridge until she learns he assaulted her uncle, demands he find Jabez and apologize. Breckinridge sets off for Cordova, learning along the way that an elderly couple named Hopkins were robbed of their buffalo hides there. He vows to investigate.

In Cordova, Breckinridge is enraged by an anti-cowboy sign posted by the buffalo hunters. He tears it down and confronts their leader, Bull Croghan, in the Diamond Bar saloon. After bashing Croghan with the signboard and battling a bartender and Joe Emerson (the saloon/store owner and town boss), a full-scale gunfight erupts. Breckinridge barricades himself inside Emerson’s general store and fends off dozens of armed hunters.

Meanwhile, the buffalo hunters try to retrieve a cannon to blast him out. As they struggle with it, Breckinridge discovers Jabez Granger in the act of setting fire to the store. He pursues and subdues him, forcing an apology. Just then, the store explodes—likely from a stray bullet hitting a powder barrel. Breckinridge survives and returns to the saloon area where he commandeers the cannon and fires it at the crowd, tearing their clothes and knocking them into a gully.

He then discovers a hidden cellar beneath the store full of the Hopkins’ stolen hides, all marked with their red Circle A brand. Realizing Joe Emerson is the thief, he forces him at gunpoint to return the hides and the stolen wagon and team. On the way back, Breckinridge restores the goods to the grateful Hopkins couple, who tearfully thank him.

Returning to Panther Springs, Breckinridge is stunned to learn that Judith has eloped with Glaze Bannack—the very friend he went to so much trouble to free. She had apparently fallen for Glaze while bringing him cakes and pies in jail, and used Aunt Henrietta’s money to pay his fine and run off with him.

Heartbroken and betrayed, Breckinridge swears never again to help anyone get out of jail.