Callen returns back to the NCIS Office of Special Projects to solve a kidnapping case.

The NCIS team searches Los Angeles for the lead suspect of a murdered Iraqi businessman, a former Marine who had been hired by a private security firm to protect him.

When a United States citizen of North Korean descent is murdered, the secrets to classified software are thought to be lost until NCIS uncovers a suspect from Director Vance's past.

Following the murder of a Russian woman, the NCIS team uncovers evidence that answers who and why Callen was shot six months ago.

While Hetty is attending a Senate hearing in D.C., the investigation of a murdered Marine Lance Corporal leads the NCIS team to stolen anti-tank missiles and a dangerous militia group.

Forensic scientist Abby Sciuto joins the Los Angeles NCIS team when a murder case resembles the pattern for a serial killer she has been tracking.

The NCIS team is on the hunt for a terrorist who escaped Army custody during a secretive transfer in Los Angeles.

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.

The Special Projects team travels to Romania to search for Hetty, while delving into the history of the Comescu crime family, and their connection to Callen.

The Department of Justice target a member of the team. Leon delivers unsettling news to Hetty.