"Locke v. Jack" is an orchestral piece from the Last Episodes soundtrack. It plays during the final battle between Jack Shephard and the Man in Black stuck in the form of John Locke in the series finale.
The camera looks down from the air as Locke and Jack rush at each other. Their collision knocks them both down and sends Locke's knife clattering away. They punch each other and fall again, and Locke pulls off his pack, which has been weighing him down. But Jack kicks him and then traps him in a headlock. Locke then butts him in the chin and punches him repeatedly. The Island begins shaking, forcing Locke to steady himself and sends the knife clattering even closer to the cliff's edge.
Locke runs for the knife, but Jack tackles him. They wrestle, each grabbing the other's neck. The Island shakes harder, and an entire section of the cliff crumbles into the sea. Jack's hold begins to suffocate the Man in Black, but he manages to reach the knife. He plunges it into Jack's side, burying it up to the hilt.
Jack lets go of his opponent and puts his hand to his wound. he collapses, and Locke gets up, holds Jack down and pulls back his knife, ready to strike. Jack grabs the oncoming arm and tries to hold it back. But the knife moves down and cuts into his neck. Locke wants Jack to know he "died for nothing," but a gun fires. It's Kate, who shoots the Man in Black, freeing Jack. Kate provides the one-liner, "I saved you a bullet", in a call back to the Man's earlier quip "You can save your bullets") when he was invulnerable.
He falls, but the Island still shakes. Jack kicks him off the cliff and he dies on the rocks below.