‘NCIS’ Season 18 Episode 2 Spoilers, Live Stream: How To Watch Milestone 400th Installment

Season 18 Episode 2 of "NCIS" marks a milestone for television's longest-running police show -- its 400th episode. After being on air for more than 15 years and 17 seasons, "NCIS" is set to air its landmark episode this week. Fans can live stream and watch the episode online from anywhere across the world.

Last week, Mark Harmon (Leroy Gibbs) and Sean Murray (Timothy McGee) returned to their crime-fighting duties as the eighteenth season of the show premiered. Featuring a cold case, Gibbs and Joe Spano’s Tobias Fornell went after a leader of the drug ring in an episode titled "Strugeon Season." Later, it was revealed the supplier of the counterfeit drugs was once connected to Fornell’s daughter. The premiere tied in with the storyline featuring in the 2019 episode “Musical Chairs.”

"NCIS" Season 18 Episode 2 is titled “Everything Starts Somewhere” and it will jump back even further in time. The special 400th episode will roll back a few decades to unveil some origin stories of the heroes of the show.

Spoilers suggest a full dramatic ride as they visit the past of Naval Criminal Investigative Service's (NCIS) team commander Gibbs and his long-time friend medical examiner Donald Mallard, also known as Ducky. The highly-anticipated segment features the early days of Gibbs’ career and the time when he had just met the young Ducky.

Viewers can expect some nostalgia and lots of action when the pair begins one of their first murder mysteries as special agents in the agency.

“Flashbacks reveal the murder case that first introduced young Gibbs to NCIS and his introduction to young, new-to-America Ducky,” reads the official synopsis.

A recently released preview of the 400th episode gives a glimpse at young Gibbs and Ducky and a return of their common enemy. The promo teases a “travel back in time” to the day when Gibbs and Ducky met and solved their first case together.

“Well, the story revolves around their first meeting and they’re at a crossroads in their lives, each of them. I won’t go into the exact nature of the crossroads, but it’s a very pivotal moment in both of their lives and they’re able to help each other get on the path that leads them to where we find them in the present day,” showrunner Steve Binder said of the episode in an interview with TV Line.

Fans can watch "NCIS" Season 18 Episode 2 online via streaming on CBS All Access after its broadcast Tuesday, 8 p.m. ET on CBS.