The latest "NCIS: Los Angeles" featured a college friend of Eric's who became the focus of an NCIS investigation.

In "Zero Days," Eric (Barrett Foa) is playing an online game with his friend, Ira, when his loft is attacked. Ira is a hacker for hire for the DOD who specializes in finding Zero Days, the code flaws in computer systems. Sam (LL Cool J) and Callen (Chris O'Donnell) go to his loft to investigate, and he tells them that federal agents tried to murder him.

Ira is convinced there is a conspiracy, so the team creates a conspiracy for him to believe. The team makes him believe that Eric has been charged with cyber-terrorism, and that Ira was helping him.

The team finds out that his Zero Day exploits a weakness in a Russian GPS that allows someone to get control of nuclear missiles. They also find out that the DOD didn't hire Ira has a hacker. They discover the deal was set up through Neidra Industries. Eric hacks into the system and discovers that they have the Zero Day USB, but it ends up falling into very wrong hands.

Eric goes out in the field and saves the day by apprehending the USB as there is a shootout going on around him. He also considers permanently joining the NCIS team.

Meanwhile, Granger (Miguel Ferrer) is trying to find a missing Kensi (Daniela Ruah) in Afghanistan.

Kensi sees Jack while she's in the cave, but when she calls to him, he gets knocked out and is dragged in with her. Jack says he heard she's been captured, so he was trying to get her captors to release her. She tells him that her mission is to kill him because he's allegedly helping militants. He denies the allegation, and says he is only helping people from his village.

He said he feels free and at peace where he is. He tells her that he has been accepted by a tribe, has converted to Islam and even got married and had a child. Then his wife was killed in a drone attack, so he contacted U.S. authorities about the deadly strike. But all they did was send in CIA operatives to recruit him.

Kensi then comes up with a plan to escape. She throws her clothes into the fire to smoke up the cave so they can have a change to escape while their captors investigate what's going on.

Instead, two men come in and take Jack away, and leave Kensi. 

Granger tells Hetty (Linda Hunt) what happened, and also says that she needs to tell him everything she knows about the mission. 

On the next episode, "Spoils of War," "Hetty decides to send the NCIS team to Afghanistan after she learns Kensi is missing and the Taliban may have her."

Also, there will be some transition issues when Kensi eventually comes back to the states, which could affect her partnership with Deeks (Eric Christian Olsen).

Renee Felice Smith, who plays Nell on the series, told TVLine: "Hetty kind of encourages Kensi to stay close to home, in ops," Smith previewed. "So she and Eric Beale get to share some time together, which gives Nell and Deeks some time together out in the field."

Watch the promo below for "Spoils of War," which airs Tuesday, April 1 at 9 p.m. EST on CBS.