Three girls riding in a convertible are almost hit by a prisoner bus which runs off of the road. Three prisoners kill their guards, escape the bus and take their car.

The three prisoners are Lieutenant Ted Nash who was imprisoned because of a bar fight, Levon Dalton who had been sentenced for striking a commanding officer, and a Russian by the name of Dmitri Babakov.

Babakov was a smuggler, extortionist, arms dealer, human trafficker and spy, who had been interviewed by the Navy.

NCIS tracked the stolen car to a house, and arrived there after shots had been fired and a trooper had been killed.  On storming the house, they only found a little boy who was hiding in a cupboard. 

The boy told them that he'd heard voices, one of which sounded foreign, and that the word "grave" had been mentioned.

Meanwhile, in her autopsy of some of the murdered personnel, Dr. Wade discovered that their large intestines had been damaged. 

The team interviewed the former girlfriend of Ted Nash, and learned that he and his family had been permanently stationed in Hong Kong.

As a result of their BOLO, the team got a hit on a video camera footage of Nash and Babakov, in which Nash showed the camera a symbol on his arm - the symbol for "danger".  This made them think he was Babakov's prisoner, and that he wasn't with him of his own accord.

After learning that Nash was on his way to a hospital, they grabbed him there and took him in custody.

Nash had been at the hospital to visit his dying mother.  LaSalle offered to take him back there so he could say goodbye to her before she died - in exchange for information on Babakov.

They learned that Babakov had been through a series of interviews.  Pride wanted to know what those interviews were about but could only receive a heavily redacted file.

Pride reached out to Gibbs to get the unredacted version, and learned that Babakov was cutting a deal in exchange for intelligence about a mole in the Navy.

They then realized that Nash had extensive martial arts training - the type that allowed him to inflict injuries consistent with large intestinal damage.  Nash was the mole, and had been trying to play all sides.

Director Vance instructed Pride to bring Nash in alive, so that they could find out what kind of intelligence he'd been passing on, and to whom.

While on the run, Nash asked Babakov if he had revealed his name.  After assuring he hadn't, Nash shot him dead.

The NCIS team figured out that he was heading to a grave dock in order to escape to a ship in the Gulf.  They caught up to him in a building but he was able to fight off LaSalle.

Then, Nash grabbed Brody in a death grip while Pride pointed a gun at him.  Pride told him to let her go, and when he didn't, Pride shot him point-blank in the forehead, killing him.

Vance angrily read Pride the riot act for disobeying his order to bring Nash in alive.  Pride reacted by saying he'd do it again, and offering his badge if Vance wanted it.