The story of a young boy who witnesses Billy the Kid's encounter with Sheriff Pat Garrett.
New Mexico Territory, 1880. Rio Cutler and his older sister Sara must abandon their home after an unfortunate event happens. In their desperate flee to Santa Fe, they cross paths with the infamous outlaw Billy the Kid and his gang, who are ruthlessly pursued by a posse led by Sheriff Pat Garret.—@yusufpiskin
Rio Cutler (Jake Schur) is forced to go on the run across the Southwestern United States to save his sister Sara (Leila George) from his villainous uncle Grant Cutler (Chris Pratt). Grant had taken Sara after Rio killed his own father when he pleaded with him to stop hitting his mom. His father didn't stop, and Rio shot him. Furious over his brother's murder, Grant attacks Rio, receiving a stab wound in the process. Rio and Sara fight back and escape. They take shelter in an abandoned shack; intending to meet their mother's friend in Santa Fe.
On the way they encounter Billy The Kid (Dane DeHaan) and his gang including Charlie Bowdre (Chris Bylsma), Pete (Keith Jardine), Wilson (Charlie Chappell) and Dave (Chad Dashnaw). Rio shows a picture of his mother to Billy, who reveals that he too killed his father in defense of his mother. The same day, he encounters Sheriff Pat Garrett (Ethan Hawke) on the hunt for the infamous outlaw Billy the Kid.A gunfight ensues, and Garrett's posse takes the gang prisoner. Billy is surrounded by Pat's forces and decides to surrender.Sara warns Rio not to go outside, fearing he will be hanged if he reveals he killed their father. Seeing this as a chance to get safely to Santa Fe, Rio runs outside anyway. Garrett begins to question Rio and Sara; they tell him that their mother died and while travelling to Santa Fe, they were separated from their father. Garrett seems suspicious, but takes them along.
Rio finds himself increasingly entwined in the lives of these two legendary figures as the cat and mouse game of Billy the Kid's final year of life plays out.The posse stops at a Mexican ranch where Billy sees his lover and promises to return. While Billy antagonizes Garrett during dinner, Rio slips him some butter to escape from his wrist shackles and Billy threatens to kill a deputy, if not set free. Garrett produces a gun and threatens to shoot gang member Dave Rudabaugh, who Billy is still shackled to at the ankle. With no escape possible, the situation is defused. Later, Garrett tells Rio about the first man he killed and asks him if he has anything he wants to tell him, but Rio says no.
Sara tells Pat that she and Rio got lost in a storm and separated from their father. Pat suspects something. Rio wants to confess to Pat, but Sara keeps warning him that confessing will lead to hanging.At Santa Fe, the local Sheriff Romero (Vincent D'Onofrio) wants to Hang Billy, but Pat is firm that Billy is a federal prisoner & will Hang in Lincoln County. He commandeers a stagecoach to transport Billy further, and Sara uses the distraction to run away with Rio. Pat manages to avoid a gunfight with Romero's men and takes Billy away.
But Grant was waiting for Sara and Rio in Santa Fe. He takes Sara and tells Rio that he will make her a prostitute.Rio sees Dave about to be hanged and Dave informs Rio that Billy is also about to be hanged in Lincoln and gives him a letter from Billy, which claims he knows where Sara was taken.Rio has no option but to travel to Lincoln County and seek Billy's help to rescue Sara. Apparently, Billy knew what Grant was up to and knows where he is taking her.Ultimately Rio must choose which type of man he is going to become, the outlaw or the man of valor, and will use the self-realization in a final act to save his sister. Rio steals a horse, gets a gun, rides to Lincoln and goes to the jail to visit Billy, but deputy Bob Olinger (Adam Baldwin) turns him away. To get into the jail, Rio robs a bank in a half heart manner and is shot by another deputy. In jail, Billy plots to escape and offers to bring Rio. Garrett once again asks Rio if he has anything to tell him, again he says no, and Garrett leaves town.
Billy takes advantage of Pat's absence to escape with Rio. But on the way Rio realizes that Billy has no intention of going for Sara. His plan is to kill Pat, reach his girlfriend's town and then hightail it to Mexico.
Rio is heartbroken and leaks Billy's location to Pat. Pat ambushes Billy and kills him.Garrett catches up with Billy at the ranch and kills him. Realizing Billy could not have helped him, Rio tells Garrett the truth about his father and his sister. They go to the brothel in Puerto De Luna and Rio looks for Sara while Garrett encounters Grant. Grant tells Garrett about a time he saw his brother engaging in incest; when he told his father, he was beaten harshly and told to keep his mouth shut. Rio emerges with Sara and Grant takes Rio hostage during a skirmish that includes gunfire and Sara shooting one of the men that raped her from her uncle's gang.
Garrett chases Grant outside, where Grant threatens to kill Rio if he isn't let go. Garrett tells Grant that witnesses will attest to how he ran off from Pat Garrett like a coward. Grant says that's not true, but Garrett says it doesn't matter what's true, it matters the story they tell when you're gone.Garrett challenges Grant to a fair gunfight, which he accepts, and tosses Rio aside. Sara emerges from the saloon suddenly, distracting Garrett. Grant makes his move, but Rio shoots him in the head.
Before Garrett leaves town, he tells the siblings they have good in them and plenty of life to put to good use. As Sara and Rio ride off, Rio encourages Sara to remember what she once said to him, that it isn't wrong being afraid, you have to keep trying and keep moving until you find some goodness in life.