A private jet belonging to Blye Industry takes off from New Orleans to Washington, but there's no radio contact. On a fly-by, the Navy discovers that all aboard are dead.
The plane has a full tank of gas, and there is a danger it may go down in a populated area. The Navy informs NCIS that unless they have a better way to bring it down, they need to shoot it down while it's over the wilderness area.
Abby and McGee hack the satellite from where the plan gets its GPS coordinates. They fool the plane's autopilot into believing that the plane is too high, so the plane descends into a crash landing in a wooded area.
NCIS Special Agent Dwayne Pride (from NCIS: New Orleans) calls Gibbs, and tells him that Abby's brother Luca was on the crashed plane.
Gibbs and McGee check the downed plane, finding the four people listed on the flight manifest, plus one badly burned body wearing a coat belonging to Luca Sciuto, Abby's brother.
Down in the lab, Abby comes down to identify the body that supposedly belongs to her brother. She tells Ducky the body isn't her brother.
The NCIS New Orleans agents find a large amount of cash, a couple of guns and a listening bug in Luca's apartment.
McGee says that Commander Gil LIvely, one of the passengers on the downed plane was flying to Washington to meet with the Secretary of Defense.
Luca sends Abby a text message in code to tell her where to meet him in New Orleans. She tells Gibbs and McGee.
The blood work from the dead bodies shows that they were poisoned to death.
The head of Blye Industry is ducking calls from the Secretary of Defense.
Tony and Abby search for Luca in a fairground in New Orleans.
McGee identifies the poison used on the plane passengers as a toxic chemical found on South American poison dart frog. The eating utensils found on the plane were coated with the poison.
Camera footage from outside the plane the night before it took off shows only one person bringing food and utensils to the plane: Luca Sciuto.
Abby finds her brother. Tony arrests him.
Luca tells Abby that he worked for Blye Industry, and that he took in a woman named Eva who claimed to be escaping an abusive husband. He says she never allowed him to take pictures of her, constantly changed cell phones and never told him her last name.
Abby works on a caricature of Eva and identifies her as a Russian agent named Eva Azarova. She works for Russian Counselor Anton Pavlenko.
Eva calls Luca but asks to speak with Gibbs. She asks him not to contact Pavlenko via official channels, and that lives depend on keeping their communications secret.
Abby triangulates Eva's cell signal to an area of the city that contains a Russian restaurant. Gibbs and Tony rush out to try and apprehend Eva.
Tony and Gibbs enter the restaurant and find Pavlenko. He tells them that Eva's phone call was a technical ruse, and that Eva is in New Orleans.
Pavlenko tells Gibbs he's helping him and is going against his own government. He says the man who was found burnt beyond recognition on the plane was one of his agents. The man was going to represent Pavlenko in a meeting with the Secretary of Defense. He says he's trying to prevent a war.
Pavlenko says that his Russian government was planning to steal a technology that Blye Industry was developing for the American government. He says he spent two days in New Orleans and that what he saw there confirmed everything.
Pavlenko talks about something called "Project Mantary." He's about to say more, but he collapses and dies of a poison.
Ducky and Palmer head to New Orleans. A van pulls out in front of them, cuts in front of them and comes to a stop. Three men jump out holding machine guns. Ducky and Palmer raise their hands in surrender.