Gibbs starts his career as a newly minted special agent at the fledgling NCIS Camp Pendleton office, where he forges his place on a gritty ragtag team.

As Leroy Jethro Gibbs prepares for his first Christmas without his wife and daughter, flashbacks reveal the unlikely journey that led to his first day on the job as a special agent.

Vera receives an unexpected call from Bugs, who claims he's ready to answer more questions from prison after being identified as the sniper known as Sandman.

When the murder of Pedro Hernandez is unearthed, Gibbs faces a reckoning. But when he needs his team most, the loyalty of one is brought into question.