Hanna and Callen meet with Frank at the safe house. He says Su was very secretive. He says there were parts of the work he kept to himself. They ask him if Sally knew anything. Frank believed Sally was just a financier. Hanna says Kai doesn't know that the technology died with Su.

During their car ride home, Callen says he doesn't trust Frank. Hanna says he thinks it is because he is a buerocrat like the ones he dealt with as a kid. Callen tells Vance that Frank stated that Su took his secrets to the grave. Callen says he doesn't believe Frank because he is a beurocrat. They see Daniel's brother Jimmy walk out of his apartment with his wife Aimee. Hanna notices a rifle on a rooftop and tells them to get down. Several shots rain down, but the team is safely hidden behind a van. Meanwhile in the building, Kai breaks down her gun and escapes.

Callen and Hanna bring Jimmy to the safe house. Hanna reports that Kai took all the evidence including her shell casings. Jimmy says his brother left nothing for him. Aimee asks what will happen now. Callen says they will try to neutralize the threat, but if they can't they might have to join the witness protection program. Jimmy refuses to run. Eric discovers Kai's car in a traffic video. He learns that she is registered at a hotel. After Callen and Hanna leave, Kensi notices that Jimmy and Aimee are quietly arguing. She asks Nate to position himself so she can read their lips. She sees him beg her not to tell. Kensi figures that Jimmy knows all of Daniel's business.

Vance, Callen and Hanna arrive at the hotel. Callen figures that the case is personal to Vance. Vance uses a key card and enters Kai's room. He notices pictures of Daniel on her desk. The phone rings and Vance picks it up to speak to Kai. She tells him she is flattered that he is looking for her himself. Vance gets on his cellphone and calls Callen as he talks to Kai. Callen instructs Eric to trace the call. He informs them the call is coming from the hotel. He directs them to her cell phone location. They enter a gym and find she is gone. Callen picks up the phone and talks to Vance. He tells Callen that Kai said she didn't kill Sally Morris.

Back at headquarters, the team wonders if they should believe Kai. Dom says Daniel Su's security system can tell how many people were in the house. He says Sally let her killer inside the house since he knew him. Eric finds that Jimmy and Frank called each other often. Callen learns that Jimmy knew more than he admitted. Vance figures they need to have Jimmy admit to his involvement. They figure that since he didn't meet Dominic, they can use him to go undercover.

Later, Hetty dresses Dominic up as a police officer. She tells him the word to call for backup is shadows. She informs him the uniform is new. Jimmy leaves the safehouse and meets with Dominic on the street. Dominic tells him he was the first officer to discover Sally. He says that before she died she whispered a name to him. At the headquarters, Eric learns that someone is trying to trace Jimmy's cell phone. Vance calls to abort the mission. He tells Dom to bring Jimmy to safety. Kai shoots at Jimmy but misses. Callen chases after Kai and hears her driving her car down the parking lot. He shoots at her driver side as it passes through an opening. He jumps down a flight of stairs and shoots at the vehicle. Callen opens fire as the car leaves the garage. The car slams into a truck. Hanna opens the door and finds it empty, but bloody. Vance learns that Jimmy denied killing Sally.

Abby calls Vance and informs him she is done with her analysis. She says there are no prints at the scene. She finds a smearing mark on the lamp. Kensi is called. She tells Aimee the killer wore two rings on her left hand. Aimee realizes she is caught. She says Jimmy was the smart one of the family and Frank suspected he hired the wrong brother. Aimee told Sally the truth after Daniel was found dead. She admits she killed Sally after she threatened to deport Jimmy.

Later, Vance arrives at the scene. Callen and Hanna report that Kai escaped. Vance sees that Kai lost a lot of blood and figures if she doesn't get to a hospital that night, she will die. Nate tells the team that Vance will never believe Kai is dead until he kills her himself. Dominic realizes he lost Hetty's button camera. Hanna realizes he is going to get in trouble and helps him look for it.