A fight in an alley behind a bar leaves one Marine corporal dead and another critically ill; the gang investigate; Gibbs says that the event was an ambush, not a bar brawl. The survivor is from Gibbs's hometown; Gibbs and Ducky agree that the survivor may have been the target of the attack. McGee and Ziva go with Gibbs to the town, where they meet Gibbs's father and others; they learn that everyone in town believes that the Marine died four years ago. Flashbacks abound; Gibbs finds lies and liars. McGee and Ziva gather evidence, but it disappears, so Tony and Abby join them, and they get more evidence; then they all put the pieces together and nail the bad guys.