It’s 1871. 12-year-old Billy McCarty and his immigrant Irish family have to leave New York and travel west to seek new opportunities. But the journey proves fatal for some.

Billy, on the move again, ends up in Chihuahua, Mexico, with a new Mexican friend called Segura. Together they enjoy several risky escapades – but in the end, Billy risks losing his life.

The Lincoln County War is on the verge of kicking off in a big way. Billy has joined Englishman John Tunstall in his commercial battle with Major Murphy and the House, but even bigger players lurk in the background and the stakes are high.

The war has started, but John Tunstall is hospitalized by a smallpox outbreak.

Kathleen and her sons Billy and Joe travel on to Santa Fe. Life is hard, but she meets and marries a man who might change everything for the better – only to find that he makes it a lot worse.

Billy bumps into a new character called Pat Garrett, who is riding with Jesse and the 7 Rivers Gang. Billy joins them – but law makers are already closing in. They plan to flee to Lincoln County – but not before Billy fulfils one last promise.

Billy rides into Lincoln County to join up with the gang, who are working for Lincoln’s most powerful boss, Major Murphy. Murphy wants them to get rid of his new competitor, John Tunstall. Billy finds himself torn between the two rivals.

We are on the eve of the Lincoln County War. Jesse and the gang are encouraged by Murphy to ramp up their attacks on those famers, mostly Mexican, who have signed up with Tunstall. It’s the last straw for Billy, and he decides to change sides.

Antrim, Kathleen and the two boys relocate to Silver City, trying to start a new life, but all their dreams are shattered — and Billy loses everything.

Billy finds fresh trouble when he falls in with a character called Alias. He kills a man in self-defense and ends up on the run, and then in the arms of a young woman — who also happens to be the girlfriend of Jesse Evans.

Billy and the Regulators hear news that John Tunstall’s ranch is going to be raided.

The Regulators have been on the defensive since the start of war, but Billy draws up a plan which could bring the war to an end.

The del Toboscos fail to repay their debt, leading to an ambush by the 7 Rivers Gang. Billy vows that he and the Regulators will take over Lincoln and clear out the thugs. But, there's a new Sheriff.

Billy and the Regulators turn McSween's house into their HQ, and are supported by the Mexicans; a confrontation with the 7 Rivers Gang leads to a fusillade of bullets.

With Lincoln on lockdown, Murphy's House celebrates; Regulators look-out shoots a soldier.

Frustrated by Billy's ability to evade capture, Thomas Catron devises a scheme to lure Billy back for his arrest; The Regulators attack the jail while Billy, aided by Dulcinea, escapes once again.