A man leaves prison with nothing but the shirt on his back. He makes his way into town, has sex with a local bartender and steals a car. He arrives in Manhattan to see an old acquaintance, a cross-dressing hair stylist named Job, and proceeds to destroy the computers in the office until Job agrees to give up an address. Leaving Job's, the man is chased by a Ukrainian mobster who shoots at him through the New York City streets. He escapes and steals a motorcycle, riding into the town of Banshee, PA.
In Banshee, he sits at a local bar and shares a drink with the bartender, a former prizefighter named Sugar Bates. Two men walk into the bar looking to rob it, but Lucas Hood, the newly-arrived sheriff-to-be, has other ideas. In the ensuing altercation, the thieves and the sheriff are killed. While disposing the bodies with Sugar, the man takes a call on Lucas's phone and decides to his assume his identity.
The new Lucas visits the home of Carrie Hopewell, the wife of the town's district attorney, Gordon. Lucas and Carrie, whom he calls Ana, share a past from the life she had before arriving in Banshee. Lucas asks for his cut of the diamonds they stole from "Rabbit." She pleads with him to just leave her and her two children alone. "I don't get the girl, I don't get the money," he tells her. "I spent 15 years thinking about this day; this is not how I pictured it."
Lucas has Job hack into law enforcement databases to verify his cover. He meets with Dan Kendall, the town's young mayor, and is introduced to the sheriff's deputies: Brock Lotus, who resents Lucas for getting the job he wanted; Emmett Yawners and Siobhan Kelly.
While making rounds with Brock, Lucas springs to action when he sees a group of local thugs, the Moody boys, beating up a group of Amish men. Kai Proctor, the man who controls all of Banshee's criminal enterprises and most of its legal ones, arrives and puts a halt to the fight. He forces Cole Moody to apologize to one of the Amish men, who happens to be Kai's estranged father. Later, in Proctor's slaughterhouse, he savagely beats Cole.
Lucas robs a local pawn shop, stealing its safe and the championship belt that used to belong to Sugar. Soon after, he is sworn in as sheriff and invited to a party in his honor at Proctor's home. Away from the gathering, he invites Carrie to open the safe he stole, but she shuts him down. After Carrie walks away, Cole Moody arrives and knocks Lucas out from behind. He drunkenly shoots through the party and takes dead aim at Kai. But before he can fire, he's taken out by a single shot, fired by Lucas.