The episode starts with a group of men picking up trash as part of their community service when one of them sees a body. The victim is Marine Lance Corporal David Austin. It appears as though his motorcycle crossed the center lane and went off the road, but Ducky and Palmer note that he has a bullet wound to the chest.

Tony’s father arrives at headquarters, and Tony hands over his key. Tony offers to make reservations for them and his girlfriend Zoe at a restaurant, but Senior says he has other plans for the three of them.

Gibbs visits Abby at the lab, and Abby says that the gun used on Austin was bought by the ATF.

Gibbs and Vance meet with Zoe at the ATF, and she tells them that the gun is one among three thousand guns that were supposed to be used for a sting operation, but somewhere along the way things went wrong, and now the guns ended up all over Mexico and most have been used in an assortment of crimes. Tony volunteers to work with Zoe, while Bishop and McGee will trace Austin’s steps from the time he left his parents’ farm up to the time that he was shot.

Abby learns that Austin didn’t have enough gas to make it to his destination. He passed a gas station along the way but didn’t stop, so Bishop and McGee go the gas station. In the station’s video footage, they see Austin staring at a car then turning around and following it.

Tony and Zoe arrive at Tony’s place and they hear the fire alarm beeping. Senior just burned their dinner and rearranged his furniture. Tony tells Zoe that something like this always happens when his father is around. Senior overhears this and is very hurt by this.

Meanwhile, Abby is able to zoom in on the video footage and sees a woman in the car that Austin followed, and it appears as though the woman is asking for help. The car is registered to a Jennifer Vickers, but the woman inside the car appears to be younger.

Later, Tony tells the team about his father, and Gibbs tells him that Senior is crashing at his place. Tony tells Gibbs that he should never worked with Zoe on the case.

Bishop and Gibbs visit Jennifer Vickers at her hotdog cart, and she says that her daughter Emma took the car and she hasn’t seen her in weeks and that she fell in with a bad crowd.

Gibbs returns home and sees that Senior is drinking his scotch yet hasn’t had anything to eat. As Gibbs makes a sandwich, Senior tells him that all his friends have gone somewhere and that he wants to be closer to his son. Gibbs gets a call and he heads out.

In an alley, Vickers’ car has been found along with Emma’s body. Tony goes with Gibbs to his place, and Tony apologizes to his father. He also offers to help him find an apartment.

Ducky does a rape kit on the body, and Abby finds some DNA belonging to Jamie Rivers, who was arrested a few years ago for illegally selling firearms. The team set up a sting operation, and McGee poses as a buyer. When Rivers shows up, two rangers arrive. Tony and Gibbs approach, and Rivers attempts to reach for his gun, but Gibbs shoots him before he’s able to do so.

“NCIS” airs on Tuesdays at 8 p.m. on CBS.