Granger gets into a car accident to open NCIS: Los Angeles Season 6 Episode 9.
Sam and Callen go to the accident scene to review the accident. Granger was going to fast for the road and there wasn't anyone in pursuit. Sam feels like something's not right and wonders if it's connected to the leak of Hetty's information. They believe there is a mole.
Deeks and Kensi go to the hospital to talk to Granger. He's restrained in the hospital bed. He tells them it's not safe and goes after a gun. He has a seizure and is restrained again. He was in an altered state and the doctor says it was for his own safety and those around him. The toxicology result show he was poisoned.
The poison is a form of wolfs bane. Someone put one on Kensi's desk. She thought it was from Deeks, but he didn't put it there. The poison was found all over Granger's office. The NCIS building needs to be decontaminated, but Hetty's not sure whether they should evacuate or not. She fears if they evacuate, then the person responsible will get out and poison others.
Instead of an evacuation, Hetty locks down the facility. There are three employees not in the office, so Sam and Callen go to check out one employee who called in sick. She was found unconscious at her apartment. The surveillance video system was down when the plant was put on Kensi's desk. The mole took advantage of the system being down.
Hetty asks Nell to perform polygraph on all employees. Nell finds that $50,000 was deposited into Eric's bank account. He asks for time to figure it out before reporting it and she agrees. Nell gives Hetty the polygraph. Hetty admits to treason, but not against the US. She also confesses to trying to kill Granger, but years ago.
Eric tells Kensi and Deeks about the money. They realize it was a stall tactic to keep Eric busy from other work. They hear a scream and find a co-worker hanging from the ceiling. It's Helen Trapper from Human Resources. They haven't found anything on her phone or computer. There's nothing on surveillance again due to blind spots.
Helen didn't kill herself. Deeks finds a second set of ligature marks. He walks through the crime with Kensi and they believe the killer's DNA could be under her fingernails. They do DNA tests on all the non-agents in the building. Eric is brought in for questioning and is with the others.
One of the employees holds Eric to get Deeks and Kensi to put their guns done. They found the mole. He uses Eric and another employee as shields and escapes. Kensi and Deeks go in pursuit. Eric tries to talk Carl out of escaping and gets knocked in the nose. Eric take him through the basement storage area and gives a heads up to Hetty.
Sam grabs Eric and Callen goes after Carl. Deeks and Kensi handcuff him. Carl believes he's going to get a deal for information and work as a double agent instead of having his infiltration go public. Two men show up to interrogate him at a "black site." Callen says he's actually going to a dog shelter with a bag over his head. The fear will open him up to talking.
Hetty visits Granger in the hospital. She tells him it was Carl from IT, but they don't know who he was working for. The case isn't over.