
Naval Criminal Investigative Service Special Agent Leroy Jethro Gibbs leads a group of colorful personalities in investigating crimes -- ranging from murder and espionage to terrorism -- that have evidence connected to Navy and Marine Corps personnel. The team includes MIT graduate Timothy McGee, Ellie Bishop, who specializes in international threat assessment, charismatic and unpredictable Nick Torres, and forensic psychologist Jack Sloane. Dr. Donald "Ducky" Mallard brings his vast experience in forensics into play to help solve cases.

The NCIS team jumps into motion to investigate who is responsible for a potential bioterror attack at a strip mall parking garage; Knight's father deals with a health scare while in Japan.

Dr. Mallard's predecessor, Dr. Magnus, joins the team to help solve a murder at a college fair.

NCIS works to solve the murder of a Marine private who appears to have been killed for helping an Afghan refugee; Jimmy navigates the pressure of parenting his teenage daughter, who is eager to go out on an unchaperoned group date.

The team investigates when a Marine is found beaten to death in his backyard.