The NCIS team must locate a classified device with the power to destroy Los Angeles that was stolen from a college research facility. Meanwhile, Sam tries to track down a highly sought-after Christmas present for his daughter, and Eric meets Nell’s parents.

The team's investigation into the electrocution of a college student working on a classified Navy project leads them to his inquisitive daughter, who may be the key to accessing his work.

The NCIS team investigates a defense contractor, Rebecca Larmont, designing a nuclear attack weapon after her estranged husband, Victor Larmont, says he has proof she is selling Navy secrets to a foreign government. Also, Kensi goes undercover as a professional dancer at the Cuban club where the husband works, while Deeks is undercover as the bathroom attendant.

After napalm is detected at a crime scene, the NCIS team investigates the sole casualty for possible links to terrorism.

After the chief of logistics for a naval weapons station collapses on the job, the NCIS team must determine if this is a terror threat or a stress-induced breakdown. Also, Kensi and Deeks research different honeymoon locations.

After a Navy Seal is attacked while moonlighting at a security job for a successful marijuana dispensary, Sam personally vows to apprehend the suspect out of respect for the Navy Seal brotherhood

After a Navy lieutenant disappears from the scene of a car accident, the NCIS team processes the crime scene and discovers his laptop is missing along with recently accessed confidential information for retired Navy SEALs.