The origin story of Leroy Jethro Gibbs has finally begun: CBS kicked off its much-anticipated prequel Monday from veteran NCIS writers-producers Gina Lucita Monreal and David J. North, as well as CBS Studios. And as promised, Mark Harmon returned to both narrate and to appear fireside as he journals about his life.

The formula ain't broke, and CBS's latest addition to its beloved "NCIS" franchise, focused on young Agent Gibbs, doesn't plan to fix it. "NCIS" is one of the jewels in the crown of the CBS network. It's a well-oiled machine of naval-related crime-solving that has remained one of the most-viewed shows on television for over two decades.

Mark Harmon has opened up about casting Austin Stowell as the younger version of Leroy Jethro Gibbs in NCIS: Origins.

Mark Harmon recalls Gibbs actor Austin Stowell's audition for NCIS: Origins, revealing when he knew the actor would be perfect for the role.

Even the "NCIS" origin story for Austin Stowell has a Cracker Jack opening. The impossibly rugged actor, 39, had tried to clear his mind after his February audition for "NCIS: Origins," the prequel series to the CBS police procedural (premiering Monday,

NCIS: Origins, a prequel to the long-running CBS series NCIS, premiered on the network on4. The show focuses on the younger version of Leroy Jethro Gibbs as he begins his tenure as a special agent of the Pendleton branch of the Naval Investigative Service (NIS).

NCIS: Origins' brings the early days of "Gibbs" back to the screens. Mark Harmon talks about the casting of Austin Stowell for the role of young "Gibbs".

Mark Harmon left "NCIS" in 2021, leading many fans to speculate that they'd seen the last of him playing Leroy Jethro Gibbs. However, the veteran actor couldn't stay away from the procedural franchise for too long,