A prostitute and a Navy Lieutenant Louis Freston (an intelligence specialist) are shot to death in a car.
The car Freston was driving was registered to Lex Talionas. Tony and Gibbs immediately pick up on that name, as it's also the name of a classified cold case operation they were on.
At the Metropolitan International Airport in 1979, someone detonated a bomb in the departure terminal. 100 people injured or killed. The case went cold.
Two years ago NCIS agents in Colombia recovered an unexploded bomb just like the one used in the Metropolitan airport bomb. DNA recovered on the components revealed that both were made by the same person. Admiral Tyson immediately classified the intel and created the secret op. Gibbs was placed in charge because of his prior experience in Colombia.
The suspected bomb maker is Tomas Orlando. For the past six months NCIS has been trying to get a DNA sample to confirm that he's the bomb maker.
Abby finds fingerprints on Freston's car that match a pimp by the name of Edward "Collarbone" Rosario.
Admiral Tyson informs Gibbs that Freston had developed the prostitute Lolita Cortes as an asset because she had intelligence about Orlando. The reason Freston and Cortes were meeting was because she was going to give him a sample of Orlando's hair, which she had sewn into the lining of her purse. Intelligence was then going to assess the DNA on the hair to see if it matched the DNA of the airport bomber.
After killing Freston and Cortes, their killer took her purse and fled.
Ambassador Edmunds tells Gibbs about intel about Orlando: he is scheduled to meet with his top lieutenants at a location. Tyson is scrambling a Seal team to capture or kill Orlando - and NCIS has twelve hours to verify that Orlando is the valid target.
Ducky informs Gibbs that he found a tattoo on the hooker's behind, which someone tried to scrape off. Bishop says it's a mark of ownership from Rosario. She tells him she traced the art to a particular tattoo parlor.
Tony and McGee bring Rosario in for interrogation. They also bring in the purse with the DNA.
Rosario tells Gibbs that he took Cortes' purse because any money that she had belonged to him. He says that she quit working for him, but that he found her working in his turf, and that he had to send a message to his girls. He claims to know nothing about DNA samples.
Abby informs Gibbs that the DNA found in the purse belongs to Orlando. Gibbs informs Commander Hankos, who green lights the Seal op to capture or kill Orlando. The Seal team breaks in but discovers that the building is vacant. They find a partially destroyed laptop, with an intact hard drive.
Gibbs sends McGee and Abby to an aircraft carrier near Colombia to assist in decrypting the hard drive.
Abby finds DNA evidence that may tie in Orlando's niece - Dr. Susanna Soto - with her uncle. The team discovers that Soto does family therapy. Gibbs sends Bishop and Tony in to pose as parents to attend one of her parenting classes, in order to obtain data from her laptop.
When Tony and Bishop arrive at the class, they discover that there was a mixup, and that it's actually a couples' intimacy class.
Tomas Orlando walks into NCIS and tells Gibbs he's seeking asylum from the U.S. He claims to have had nothing to do with the airport bombing, and that he was being set up. He offers Gibbs a sample of his hair to test.
After Ducky tests Orlando's DNA they discover it's not a match for the DNA from the airport bomb.
Abby discovers a keylogger program embedded on Orlando's laptop, which points back to Ambassador Edmunds. Vance grills her on it, but she pretends to lose her video connection.
MPs capture Edmunds and deliver her to NCIS for interrogation by Gibbs. She asks to make a deal.
She claims to have acted to frame Orlando because she and her family were being threatened. She tells Gibbs the man who threatened her was Armand Luna, a Colombian drug lord.
The U.S. Navy launches a drone strike against Luna's compound.