Abby tells Gibbs that since their Jonas Brothers costume debacle last year, Vance banned all costumes. She finds that a vehicle on the video tape has a livery number which means it was checked out by a marine. Abby says she found paint thinner in Korby's stomach that was ingested while he was still overseas.

Tony reports that Sara was married three times, each time to a Marine. They meet with Korby's CO Barnes who wrote Korby a bad review. He explains that half of his men loved Korby since he was a joker. He says he was on base when Korby died. He explains that Korby thought he had stomach problems due to sickness. He suggests Gibbs talk to Private David Singer, a marine who had a falling out with Korby.

Gibbs meets with David in the field and ask him about his work with Korby. He says Korby showed him the ropes, but kidded around too much in Afghanistan. He explains when people were dying, Korby kept on playing pranks. He says that no one in the squad would ever kill him. He tells them to meet with Chris Norton, a high school friend of Korby.

Later, McGee says Korby's pranks caused his unit to receive bad reviews. In the lab, Ducky says he found multiple abrasions on Korby. He says he was hurt before he was poisoned. Gibbs figures that someone gave him a Code Red, a beatdown ordered by a commanding officer. Gibbs figures that Korby's entire unit wanted him gone.

The team are not able to find out who checked out the car found on the tape. Abby admires Korby's pranks. She says she didn't find any murder weapon in Korby's garage. They find particles of chicken soup in Korby's body. Palmer figures that the liquid nitrogen was put in a thermos.

Tony goes to Korby's house and finds Sara and her daughter cleaning up the garage. He asks Sara if Korby talked to her about getting beat up in Afghanistan. He says it is strange that she married three Marines who died. She explains she grew up in a military family and loved men who served their country. Tony says he is suspicious of the insurance money she got after their deaths. David arrives and gives Sara flowers. He says that Korby saved his life many times and he wanted to pay his respects.

Tony starts to believe that Sara was telling the truth. McGee reports that many of Korby's former squadmates complained about Korby's pranks. They see that Barnes checked out of base when Korby died. They see that Barnes's promotion was denied because he was found to have had a lack of leadership. Tony and Ziva meet with Barnes at an Octoberfest fair. He tries to run, but Ziva pins him down face first in a plate full of food.