NCIS investigates the death of Corporal Ray Collins when his body and severed feet show up in a dumpster.
His watch GPS leads to a huge truck where in the back there's a cutting table and the hanging remains of 10 severed human feet.
All the victims were part of a motorcycle gang as indicated on the tattoos on their feet. A serial killer is on our hands.
Thanks to Tony and Ziva's sleuthing, the evidence points to Collins as being the mastermind behind the killings.
It’s discovered that Collins was working for a Mexican drug cartel and to prove that he completed a hit he had to bring back the victim’s severed foot.
Collins must have gotten in the way of the competition, however, as he was killed the same way he killed his victims. The killer's killer turns out to be the initially cooperative bar owner, Velvet Road, who was managing the dealers for a rival cartel.
At the request of Alejandro Rivera, of the Justice Department in Mexico, Abby is invited to speak at a law enforcement symposium there.
Vance tells Abby that McGee will be her escort.
While in Mexico, Abby debriefs the students on a 20-year-old cold case where drug dealer Pedro Hernandez was gunned down and killed.
While at the crime scene Abby, McGee and the students are cornered by Paloma Reynosa, head of the Reynosa drug cartel.
Paloma realizes why Abby is there and offers Abby a sniper's bullet attached to a necklace around her neck - evidence left behind at the scene.
Abby requests that they exhume Pedro’s body and fly it back to DC for further investigation. There, it's confirmed what she already knows - that Leroy Jethro Gibbs is Hernandez's killer.