After being captured by the head of the Reynosa Cartel while attempting to save Michael Franks, Gibbs realizes that his past has come back to haunt him while Ziva, having passed her citizenship tests finally becomes an official U.S. citizen.
Gibbs's captor, Jason Paul Dean is revealed to have been working for Paloma Reynosa, head of the Reynosa Cartel.
It's shown that Alejandro Rivera is Paloma's younger brother and both are children of the drug dealer, Pedro Hernandez whom Gibbs murdered in revenge for Hernandez killing Gibbs's first wife, Shannon and their daughter, Kelly nearly twenty years ago.
Jason Paul Dean returns to the U.S but is soon killed in a gunfight between his men and DiNozzo, McGee and Ziva who are attempting to arrest him although McGee suffers some injury to his forehead and face caused by flying glass.
Ziva passes her citizenship test and is sworn in as an official American citizen.
Paloma orders that Gibbs begin working for her or risk having everyone he cares about die on her orders.
Tony heads to Mexico, tasked with keeping an eye on Alejandro Rivera.
It's later revealed that Mike Franks survived the gunfight mentioned in Patriot Down (episode) but at the cost of his right index finger.
It's also revealed that Franks has become intent on killing Alejandro Rivera.
Gibbs creates one more rule: Rule 51: "Sometimes, you're wrong".