On a country road in Virginia, Navy Petty Officer Second Class Khalil Sa’id dies – while driving his car – after swallowing emeralds. According to Ducky (DAVID McCALLUM), he was apparently trying to smuggle them in, having just arrived from his post as a translator in Guantanamo Bay, Cuba. Gibbs (MARK HARMON), Tony (MICHAEL WEATHERLY) and Kate (SASHA ALEXANDER) head to Gito to begin an initially covert investigation, meaning they must keep Sa’id’s colleague, and fellow NCIS Special Agent Paula Cassidy, out of the loop. In her interrogation of possible terrorists at Camp Delta, Paula worked exclusively with Sa’id, and they believe she may be linked to his death.
Back at NCIS headquarters, Abby analyzes Sa’id’s clothes and car contents – including his laptop -- for clues. Abby (PAULEY PERRETTE) also determines that the emeralds found on Sa’id were actually mined in Afghanistan, a finding that has grave implications. Meeting FBI translator Bill Gamal, the team in Cuba learns that Paula had success gleaning information – with Sa'id as translator -- from Nasser Al Jazair, who arrived from Afghanistan with claims that he had been picked up unfairly. After setting up their command post in barely adequate housing, Gibbs sends Tony to check out Paula’s reputation while he and Kate prepare to interrogate Nasser, who Gibbs believes gave Sa’id the fatal emeralds. At the base’s El Floridita club, Tony catches up with Paula, who suspects she’s being investigated. While there, Tony gets a call from Gibbs to bring her in: Nasser’s interrogation has revealed that Paula promised him a transfer to the camp’s far-less-restrictive minimum security.
With Paula demanding information now from Gibbs, he reveals that Sa’id has died from swallowing emeralds. Stricken, Paula is upset to hear the news, and Gibbs then orders Tony and Kate to search her and Sa’id’s apartments. During the search, they recover Sa’id’s hard drive – which is sent to Abby – and determine that he had left for good, but can’t definitively romantically link he and Paula. The team then talks with Paula again, who said she had grown concerned that Sa’id’s and Nasser’s conversations had been getting longer; in fact, she included that notion in her last report. Then, Abby discovers that Sa’id’s hard drive contains hidden Arabic messages which Bill translates.
They piece together a plan for Nasser to, on Bin Laden’s bidding, kill Bin Laden’s son- in-law – whose identity is actually not even known on base. Feeling like she should have been more aware of the plans that Sa’id and Nasser were developing, Paula agrees to participate in a ruse. With Bill as translator, they will give Nasser the minimum security he is seeking. Gibbs knows that transferring Nasser is the surefire way to find Bin Laden’s son-in-law, although they will obviously then have to work to prevent his murder. Further, once the son-in-law knows that he was ordered to be executed, he is certain to divulge further terrorist plans.
Discreetly hiding a camera on the new prison jumpsuit Nasser now wears in minimum security, Gibbs and the others monitor his goings-on from a mobile command vehicle. Not long after his transfer, with guards in place for his imminent assault, Nasser makes a move in the exercise yard to then corner his target in one of the buildings. As he grabs a homemade shiv to attack the son-in-law, the agents head in to thwart the assault, with Cassidy drawing her sig to fire and stop Nasser.