Parker and Knight discover three bodies on an old Navy ship that's about to be sunk and turned into an artificial reef, when they're suddenly locked inside by a mysterious figure. Also, Vance offers Knight a unique opportunity.

NCIS Season 21 Episodes...

• s21e01 - Algún Día
• s21e02 - The Stories We Leave Behind
• s21e03 - Lifeline
• s21e04 - Left Unsaid
• s21e05 - The Plan
• s21e06 - Strange Invaders
• s21e07 - A Thousand Yards
• s21e08 - Heartless
• s21e09 - Prime Cut
• s21e10 - Reef Madness

NCIS Show Summary

Leading this team that operates outside of the military chain of command is NCIS Special Agent Leroy Jethro Gibbs, a skilled investigator and interrogator who is smart, tough and willing to bend the rules to get the job done.

Working under Gibbs is Agent Anthony Dinozzo, a former hugging detective who joined NCIS just a few years ago, but who has instincts that can come only from working on the streets.

Joining them is Agent Abby Sciuto, a gifted forensic scientist whose dark wit matches her goth-style hair and clothes, and Dr. Donald "Ducky" Mallard, a medical examiner.

From cuddle and espionage to terrorism and stolen submarines, these special agents traverse the globe to investigate all crimes with Navy or Marine Corps ties.