During the second season of the hit drama NCIS: Los Angeles, we learn a great deal about the pasts of the team members. The undercover agents of OSP (Office of Special Projects) go undercover to apprehend dangerous and elusive criminals that pose a threat to the nation's security.
NCIS:LA gets called in to find their liason, LAPD Detective Marty Deeks, has gone missing after a target of his undercover investigation is murdered.
NCIS Special Agent Williams is murdered by a professional hit squad in Cyprus, when the hitman arrives at LAX, NCIS:LA is called in to track his every move and figure out who is the next target.
NCIS:LA is called in when two U.S Marines are kidnapped and one murdered along the U.S-Mexico border.
NCIS: LA uncovers a link to jewelry stolen from Iraqi museums when they investigate the murder of a Marine who was found in the parking lot with his hand chopped off.
The daughter of an Navy Commander is kidnapped from her home in the Angeles National Forest and buried alive.
Callen's former CIA partner, Tracey Holland, holds a Navy Recruitment Office hostage to get Callen's attention.
A Federal Agent is murdered in a shootout downtown and NCIS:LA is called in to track down the killer.
A newly retired Army Major from a elite Delta Force unit that tracked high value targets in the War on Terror is found tortured and murdered.
An infamous arms dealer, Kurt Renner, is murdered and NCIS:LA goes in search of a black book known to hold the names of weapons dealers they believe the killers were after.
In the wake of Cole's murder, Hetty is determined to find the killers as well as the black book that has destroyed so many lives.
It's Christmas time and as Carolers sing at the doorstep of a home in a quiet L.A neighborhood, gunshots ring out and the bloody figure of a man appears at the door and two men are found shot to death inside.
Two gunmen steal the body of a Muslim man, Yusef Afzal, from the morgue after he was murdered in his home.
When classified Naval documents are uploaded to a "free-press" blog site, NCIS:LA works to find the whistleblower before a group of mercenaries track them down and get a hold of U.S military secrets.
Sam's former contact and "brother", Moe, is attacked in prison. Sam and the team rush to his aid to help figure out why someone would want this model prisoner dead.
Callen is back and discovers an intruder, Niko, in his home who he takes down and finds out he works for Arkady, a former KGB operative Callen has worked with before.
Sam and Callen have spent time undercover as CHP officers looking into a gang of corrupt officers known as the Golden State Taxi Service, who give safe passage to smugglers and criminals across a stretch of major U.S highway with suspected ties to Marines at Camp Pendleton.
Deeks is shot in what appears to be a targeted hit and the team rushes to find the hit men before they finish the job. Kensi keeps watch over Deeks at the hospital while Callen and Sam track down leads in the shooting. Eric, using Kaleidoscope, locates the hit men and they are in the parking lot of the hospital where Deeks is recovering. Sam and Callen rush to the hospital where a shootout ensues and the driver is killed but the other man gets away. The team finds the two men are gang members for hire. Once they find the other man they realize this is bigger than just a couple of thugs getting revenge on Deeks. Using the burned phone they found on the driver Eric manages to discover the phone number of the man that hired the hit. Callen goes undercover to entrap the mystery man that hired the gunmen but Deeks and Kensi soon realize Deeks was just the bait and one of the other team members is the real target.
The disappearance of a Naval Intelligence Officer claiming a pro-American Venezuelan politician is a major threat to the U.S, brings in NCIS:LA when they realize he may be targeting the politician for assassination.
Kensi goes undercover as a highly trained cat burglar in order to stop a sophisticated thief from stealing antiquities from a Naval base.
A rocket scientist is killed in a satellite test chamber on the eve of his company launching the satellite into space. NCIS:LA is called in to figure out if highly secretive satellite technology has been comprised. Hetty determines Eric is the ideal candidate to pose as an FCC inspector to examine the satellite test chamber. When Eric begins to inspect the chamber where the scientist was killed, the chamber locks almost killing Eric until Nell remotely disables the system. The team tries to halt the satellite launch but are too late and the rocket and satellite explode moments after the launch. It turns out, the scientist's greedy partner and a disgruntled worker murdered him when they believed he was about to discover their plans to switch the real satellite with a dummy satellite in order to sell the highly classified communication technology, for profit, to the Turkish buyers that commisioned the satellite launch.
A childhood friend of Deeks, Ray, turned police informant has slipped out of protective custody and our team rushes to track him down before the man he put away enacts his revenge.
NCIS:LA investigates the murder of a man posing as a retired Navy Seal who was hired by a radical anti-government group to make a dirty bomb.
Hetty's sudden resignation prompts Callen and the NCIS team to investigate the reason why she would disappear in the hopes of tracking her down.