Walker working with the FBI busts an arms dealer. The man in charge pulls a gun and Walker shoots him and his dying words are for him to watch out for his brother. The brother who was out of the country training some mercenaries, upon learning of his brother's death, he takes his mercs and goes to Texas. Upon arriving he uses the FBI agent who worked with Walker to get him. He knocks him out and when Walker wakes up he tells Walker that he's going to have to take on each of his men who have been told to kill him.

A crime lord named Caleb Hooks, whom Walker helped put in prison several years ago, escapes from prison, hell bent on revenge against the Texas Rangers (because Hooks' brother had been shot and killed during a shootout, and he claims it was murder). Hooks initiates his plan by having Alex and Trivette kidnapped, then placed in a huge tank full of freezing, running water. Hooks then contacts Walker and begins playing cryptic games with Walker, in hopes of both luring his sworn enemy into a death trap of his own and stalling Walker in his efforts to rescue his friends before they drown.