The episode begins on an USS brewer, where a sailor is looking at his family photos on his phone. He accidentally drops it under the chair. Meanwhile, someone is rigging the electric box. The sailor sees a glow coming from the electric room and the sailor goes to check it. The guy who rigged the box cannot escape as the sailor is blocking the exit. He tries to find another escape. The sailor opens the door, and the room blows. Next, we see, Admiral Theodore Tully is briefing the team about the threat to the ships. He tells the team that NCIS is investigating the case and that they would be briefed further as the investigation continues. Tully thinks that the causalities could have been worse; but Gibbs tells him that this isn’t the end of it.
Gibbs tells Tully that Vance would be back from the NATO conference by the end of the week. Meanwhile, McGee prepares to go to the brewer. The chopper would arrive at Norfolk the next morning. The team is trying to find out more about the dead arsonist Bruce Johnson. Tony thinks that Bruce might not be connected to the brewer, but Gibbs tells him that the brewer was on the target list they found in his apartment. However they have no leads on him. Next, Gibbs goes to meets Duckie. But Duckie seems a little off. He says that he wants to discuss something personal, but that can wait. Getting back to work, Duckie tells him that he didn’t find much from Johnson’s body. Next, Gibbs goes to Abby to check if she could find something from Johnson’s car.
Abby tells him that she found Johnson’s paper shredder. However she has identified some part of a document with Korean characters. Gibbs asks her if she could reconstruct the document, but she tells him that she cant. But she feels it could be North Korea behind the attacks. Meanwhile, Ziva is making her weekend plans and Tony wants to know about it. She tells him to stop being nosy. Analyst Emma walks in and she has no news about the North Korean involvement. McGee comes online and talks to Gibbs and Tony. He is on the brewer. The victims were, Eric Ramsey, the sailor and Tobey Abbot, a civilian, working for Norton Turbine and he was following up some repair work. McGee tells them that Abbot should be considered as a suspect. McGee is having sea sickness. Next, Tony and Ziva meet Johnson’s widow.
She says that Johnson never knew Korean. She tells them that they were getting divorced. They leave. Just then they talk to the mailman, who tells them that Johnson did receive some mails from Switzerland. Next, Duckie arrives at Gibb’s house. He tells Gibbs that he received a lot of money after his mother passed. But now he doesn’t know what to do. He is redoing his will and he wants Gibbs to be the executor. Gibbs feels honored. Next, Gibbs and Duckie are on the brewer. McGee, Tony and Ziva check Abbot’s quarters. They find a Korean letter in a Swiss stamped envelope. Tony is surprised that everyone knows about Ziva’s weekend plans, but him. Emma examines the letter and tells them that it is gibberish. It could be a code and she has sent the letter to the cryptographers.
In the office, they learn that Abbot wanted to join the Navy and got rejected twice. It could be revenge. In Abby’s lab, McGee tells hr that Tony is going nuts as he is unable to know Ziva’s weekend plans. Its just a Pilates weekend with her landlady. But Tony’s dirty mind is thinking something else. Gibbs arrives. Abby tells him that the arson residue they found on the brewer is similar to the ones from the other fires. McGee tells Gibbs that the magazine locker is directly below where the fire was started. If the fire would have reached the locker, the damage would have been severe and the ship could have sunk. But instead of going towards the locker, the tanks ignited and the explosion took place, creating a vacuum. Next, Ziva talks to Abbot’s boss.
He tells her that he was a good mechanic and he had lobbied for the assignment. He had no family or friends. Tony texts Gibbs saying that he needs him in MTAC. In MTAC, Tony and Gibbs talk to Agent Stan Burley. He is in Naples, Italy. He tells them that he went there for an assessment of the carrier, Benjamin Franklin; it is coming to the port. He found a thermite device in the ware house that would provide supply - a nuclear aircraft carrier. Tony and Ziva leave for Italy. Meanwhile, Gibbs finds Abby sleeping on the floor of her lab and McGee is sleeping on the computer. They managed to break the code. They tell Gibbs that it is a simple code. It was in English but printed in Korean. It had instructions for Abbot as to when, where and how he needs to attack the brewer.
Next, in Naples, Stan meets Tony and Ziva. The Benjamin Franklin has arrived. Stan tells them that the thermites have been replaced by a look alike substance. Three of them will go undercover on the board to check who comes to arm the device. They don’t want to question the civilians on the board as the perp could be warned. Meanwhile, Duckie tells Gibbs that he wants to give most of his wealth to the Marine Corps Scholarship Foundation. On the carrier, Tony and Stan stake out the room and Ziva brings them food. But Tony doesn’t want to eat as he is feeling seasick. Just then they see a man approaching. They go into the room they are guarding; and checks his instructions. Stan goes into the room, waiting for the right moment to trap the man. But the man hears a noise and he hurls a knife towards that direction.
Tony and Ziva rush in to check on Stan; he is down. His weapon is missing. Tony and Ziva manage to catch the guy. In MTAC, Gibbs is relieved to see that Stan is fine. Ziva tells him that the suspect is Andre Fullerton. He is employed by Avionics Communication and is a tech rep. Gibbs tells Andre that he has no rights as he is involved in terrorism and that they are invoking the Patriot Act to fly him down to Guantanamo Bay as a terrorist; it is a threat. Gibbs asks him the name of the guy who hired him. Andre tells Gibbs that his name is Harper Dearing. But he also adds that he has never met him in person. But he says that Harper had a slight Southern drawl. Andre admits that he did all this for money. Gibbs wants Andre to be brought back for trial. McGee finds out Harper Dearing; the Southern ones.
He gets a hit on a man who is the CEO of Dorado Hills Investments; a venture capital group. He was born in Georgia and lives in Virginia. Next, Gibbs asks Abby to compare his DNA to the ones found on the code envelope. She tells him that there is a familial match. Gibbs leaves. He goes to Dorado Hills with a team. The President of the company meets the team. He tells Gibbs that he doesn’t know where Dearing is as he has not heard from him or seen him for more than a year. Next, at the office, Gibbs puts Dearing on their list of the most wanted; for attack against the US Navy. The episode ends.