A Marine is killed after helping a bank robber on a dirt bike escape from police pursuit. Gibbs and the team investigate, and Torres discovers a shocking link to his past: the robber was riding Torres's dirt bike.
It was part of one of his past undercover operations, to take down a dangerous criminal dirt bike gang, the Rosewood Boys. Torres had convinced one of the younger members, Royce, to testify against the leadership.
Now it seems like someone is literally getting the old gang back together.
Torres is frustrated when Gibbs won't allow him to work on the front lines of the investigation. He decides to go home and get his case notes from the original investigation.
When he gets home, however, he finds his old dirt bike in the garage -- and it explodes.
Torres figures it was a warning, rather than an actual attempt to kill him. He goes to see Royce, who has been in Witness Protection since testifying. They find evidence that the current leader of the Rosewood Boys, Alonzo, was the shooter.
When the team raids Alonzo's home, they find him already dead. When Abby identifies a mysterious mud-like substance found at both scenes as potter's clay, Torres immediately realizes that Royce is the real killer.
Royce demands $200,000 from Alonzo's safe so that he won't reveal that Torres planted evidence in order to take down the Rosewood Boys. When Torres attempts to arrest him instead, Royce tries to flee, only to get caught.
Gibbs later tells Torres that Royce was bluffing about the recording of Torres confessing to planting evidence.