A terrorist holds Ducky, Gerald, and Kate hostage while NCIS investigate how exactly the terror organization member got a job at the navy base.

The terrorist from Bette Noir returns with a plan to attack the President. Gibbs and his team follow the clues to reveal his identity and find Kate who is kidnapped.

A group of serial terrorists seek revenge and send Ari (guest star Rudolf Martin) on an assignment to kill Gibbs. The NCIS team goes on a hunt after him, but when they discover that Ari has a bigger plan, it is already too late... the NCIS team will have to face the death of one of their team members...

After the terrorist's attack, the NCIS team is shocked and is trying to cope with Kate's sudden death, each in their own way. Now, their mission is to collect all the possible info on Ari and find a way to stop him before he does any more damage. Meanwhile, while feeling guilty over Kate's death, Gibbs is informed that the NCIS director is leaving, and the replacement is Jenny Shepard, a woman Gibbs worked with in the past and had a romantic history with.

Still stressed over Kate's death, Gibbs is even more hurt when Ari kidnaps Ducky and decides to play with his mind. Gibbs sends Tony to follow Ziva, and after Jenny and Gibbs are almost shot to death, he is even more determined to finish once and for all with Ari, and Ziva's strange connection to Ari will be just the help that he needs.

During a routine stop for his morning coffee, Gibbs finds himself staring down the barrel of a gun, forcing him to question choices he has made in the past and present