Poddůstojník druhé třídy Chalil Said působil jako tlumočník na Kubě. Zemřel v autě cestou do Fredersburgu, když skoro zajel dva cyklisty. Dr. Mallard v jeho těle najde smaragdy, které spolykal, aby je mohl propašovat do USA. Uvízly mu v trávicím traktu, dostal vnitřní krvácení a zemřel. Gibbs se svým týmem vycestuje na Kubu. Said působil v táboře Delta v Guantanámu a v jeho autě bylo nalezeno pět neodeslaných listů zvláštní agentce Paule Cassidiové. Gibbs se snaží Paule pravý důvod návštěvy zatajit, protože je podezřelá. Všechny důkazy nasvědčují tomu, že byla Saidovou milenkou. NCIS vyslechne i vězně Nassera, o kterém si myslí, že dal Saidovi smaragdy a je do celé záležitosti též zapletený.

We rejoin our dead motorist as he is being reduced to his component parts on Ducky's autopsy table. An obstruction has been found in the lower intestine. While Gerald opens the intestine to locate the obstruction, Ducky tells an appetizing story about a sumo wrestler's gallstones. Gerald interrupts him to state that the obstruction actually is stones - a number of large, square-cut emeralds. The emeralds perforated the lower digestive tract, causing a number of conditions that led to a painful death. Ducky shares this with Gibbs, but it's not so much the stones as where the stones came from: the deceased smuggled them into the country from Guantanamo Bay, Cuba, where he was employed as a translator at the terrorist detainment facility. The deceased is identified as Petty Officer Second Class Khalil Sa'id, from Egypt, a recent transfer to Gitmo from Bahrain, and Gibbs announces that the team is going to Cuba.

Gibbs comes down to Abby's lab, where she tells him that she has a gemologist coming to look at the emeralds. She is going through all of Sa'id's personal belongings. In them, she has found a number of unmailed letters, all with the same return address: NCIS Special Agent Paula Cassidy. There is also a shirt which smells of a peculiar cologne; Gibbs tells Abby to brand it. On the way into the elevator, he runs into DiNozzo - literally, spilling his coffee in the process. DiNozzo has booked them on a flight to Gitmo; Gibbs says to unbook it, because the Navy is giving them a priority ride today.

On the plane, Tony is waxing ad nauseam about the ride - a $40 million Gulf stream aircraft. Gibbs, who is trying to work, gives Kate the file on Paula Cassidy, who is out of the loop on the case until they find out why Sa'id had her unmailed letters in his luggage. On arrival at Gitmo, they are met by Cassidy herself, who has arranged them a car and one of the nicest houses on base. Cassidy is clearly aware that she is under investigation: her files have been pulled, her interrogations cancelled, and then the top Major Case Team from D.C. has arrived on her turf. She queries Gibbs, who tells her nothing.

They enter their house on base, where Gibbs wants to get to work, but Tony and Kate are too busy fighting over the best bedroom. Gibbs gets on the phone with Abby, who has identified a second scent on Sa'id's clothing - a woman's perfume. Gibbs tells her to brand it. Her gemologist is coming tomorrow morning. He gets off the phone and Tony and Kate want him to mediate between them on who gets the good bedroom; he solves the problem by kicking them both out of it and taking it himself. He has the Wisdom of Solomon, does Gibbs.

The next morning, Tony rolls over to find that he has gained a bedmate in the night: a large iguana. With a scream reminiscent of a terrified virgin, he jumps out of bed, training his gun on the creature. Kate and Gibbs both come running, armed, and we learn that Tony sleeps in the nude. Something Kate finds very amusing. Gibbs is severely unimpressed and exits the room complaining that he needs coffee. In Abby's lab, her gemologist has arrived, bearing gifts: a bottle of Vudu cologne that Abby's mother said was something she could use. He seems dismayed when she sets it on top of her shelf with the myriad of other colognes she has purchased for use in the case. He verifies that the emeralds are real, and high-quality - each emerald is worth at least $20,000. But there's more - judging by the distinct color, these emeralds were mined in Afghanistan.

The FBI translator - Bill Gamal - arrives, bringing all the transcripts of the translations Sa'id did with an inmate called Nasser Al-Jazair. Nasser is a recent arrival from Afghanistan who insists he was picked up by mistake. An interrogation room has been booked for Gibbs for this afternoon. They dive into the files; Gibbs sends Tony out to investigate Cassidy. When he returns, his information is that Cassidy is very popular with the gentlemen on base. She hangs out at a club on base. Gibbs sends Tony to check out the club and observe Cassidy if she is there; Gibbs and Kate go out to Camp Delta to interrogate Nasser.

Tony is discussing a movie with the bartender at the club; he knows nothing about the movie or the actors. Cassidy shows; Tony flirts, but she isn't buying it. Gibbs interrogates Nasser with Gamal translating and Kate watching from observation. At the news that Sa'id is dead, Nasser reacts strongly, and pulls out his prayer beads. Tony watches Cassidy dance, and is outed by the bartender as investigating her. They verbally spar. Tony orders tequila and a beer and asks Cassidy to dance. At Camp Delta, Gibbs gets little information from Nasser. He shows Nasser a picture of the emeralds. Kate knows that Nasser already knows about the emeralds - she can tell from his body language. Nasser requests to be returned to his cell to pray; Gibbs orders him transferred to isolation instead. Nasser flips out, starts yelling in Arabic that Cassidy promised him a transfer to minimum security. Tony and Cassidy are dancing when Gibbs calls, orders Tony to bring Cassidy back to their house.

At the house, Gibbs questions Cassidy about Nasser. His transfer to minimum security was a reward for cooperation. Cassidy demands to know what is going on. Gibbs asks about the letters; Cassidy claims Sa'id was going to mail them for her because mail out of Gitmo is slow. Gibbs wants to open them; Cassidy refuses. Gibbs threatens a court order, tells Cassidy that Sa'id is dead. She finally gives them permission to open the letters. She also offers to let them search her apartment; Gibbs accepts and sends Tony to check Cassidy's apartment and Kate to check Sa'id's. They discover that Sa'id had a key to Cassidy's apartment, but she has no key to his.

Sa'id's hard drive arrives at Abby's lab. Ducky tells Abby that his mother wears Chanel No. 5 a la Marilyn Monroe. At Gitmo, Gamal reports that Nasser is extremely upset about his transfer to isolation. Gibbs cares, we can tell. He is tossing Nasser's cell. He finds nothing. In the house, he video conferences with Abby, who has found that the perfume on Sa'id's clothing is called Escada. As she says this, Tony and Kate return. She also reports that Sa'id deleted more than 20 GB of porn from his laptop before turning it in to Gitmo security. Tony reports that there is a bottle of Escada in Cassidy's apartment. Kate reports that Sa'id's room was completely bare; he did not plan to come back to Gitmo. Tony thinks Sa'id copied Paula's key without her knowledge. Gibbs insinuates Tony is thinking with his libido; incensed, Tony goes to bed. Kate defends Tony; Gibbs tells her that romance between agents never works. The voice of experience?

The next day, Gibbs meets Cassidy and questions her about the key. She says she lost a key; Sa'id could have stolen it, possibly to gain access to her computer. She kept her interrogation notes there, including a note that she had become suspicious of Sa'id's translations, which seemed shorter than the actual conversations taking place. She notes that Sa'id took leave the day after she wrote that. Gibbs tells her about the emeralds and that he thinks they came from Nasser; Cassidy remembers that Nasser claimed of constipation on his arrival at Gitmo and was given a laxative. In the lab, Abby is going through Sa'id's porn, noting that the file sizes are too large to be simple images. She finds Easter eggs hidden in the porn - secret links that hide more information when clicked. In this case, it's communications written in Arabic and diagrams of the camp. She sends them to Gibbs.

Gamal translates the letters; they discuss someone called "Son-in-law" and his movements in the camp. It turns out that one of the prisoners at Gitmo is one of Osama bin Laden's sons-in-law, and that Nasser was actually sent to Gitmo to kill him. Now they need to find this son-in-law, for which all they need to do is transfer Nasser to minimum security and wait to see who he tries to kill. For this, they must tread carefully. They put Cassidy back on Nasser's interrogations (she tells him that Gibbs has gone back to D.C. and been reprimanded); then she moves Nasser back to his old cell, and he is moved from there to minimum security as he was promised.

They set up sharpshooters to mind their target; they believe he will try to do the kill in the exercise yard. Instead, Nasser creates a diversion and slips into another barracks where he finds his target. The security guards are in the yard, so the agents all run for it; Cassidy shoots Nasser in the shoulder before he is able to kill his target. When Tony points out that he would have killed Nasser, Cassidy says no; she didn't want to make him a martyr.

Cassidy flies back to D.C. with the Washington group. Kate indirectly cajoles Tony into going and sitting with Cassidy to try and make her feel better. Kate has a great smile. Tony and Paula make up.