Clayton Reeves, as part of Operation Willoughby, impersonates a copilot for a wanted criminal mastermind, only for the plane to blow up before said mastermind even boards.
The task force is convinced that Reeves, intentionally or not, somehow tipped Chen off that he was an agent, though neither Gibbs nor Reeves believes that.
The pilot, unfortunately, commits suicide rather than risk his family's lives by talking, but the pilot's daughter's charm bracelet allows Bishop to make the connection between Chen and some Pashto communications her boyfriend Qasim had been translating.
Though the conversations seem innocuous at first glance, it quickly becomes apparent that they are actually a code, and that Willoughby had been compromised for months.
Gibbs and company quickly identify a member of the task force as a mole for Chen. Unfortunately, it's not soon enough to save Qasim, who is shot by Chen's right-hand man, Tao.
Torres and Quinn move in to take Tao down, but Tao shoots himself rather than surrender, hinting that Chen has far bigger plans in mind than simply disrupting the financial markets in New York City.
Despite doctors being able to stop the bleeding, Qasim is left brain-dead, and Bishop must make a hard decision.