LONDON (AP) — Once again, Austin Stowell is having the best day ever — all thanks to winning the role of legendary TV character Leroy Jethro Gibbs on “NCIS: Origins.”

“Every day since I got this job it has been the best day of my life,” Stowell says with a smile.

The actor has his shoulders back and chest puffed up to portray the former Marine and naval investigator, playing 25 years before audiences first met “NCIS” star Mark Harmon.

Harmon and his son Sean are behind the idea of ​​this origin story for the special agent, who appeared on screen for 19 seasons from 2003 to 2021 and solved crimes for the Naval Criminal Investigative Service in Virginia.

Stowell says he will do his best to do justice to the role that made Harmon famous and give viewers a new perspective on “how the hero was born.”

Harmon, who does a voiceover and occasionally appears on the show, has been very supportive of Stowell, making himself available to talk about life, visit the set, and even text messages (something Gibbs would never do in a technophobic way).

“Mark and I talk a lot about what it means to be the leader of a team, what it means to be a leader of this set and this crew,” he says. “These conversations have been invaluable to me because I don’t know what it’s like. I’ve never been No. 1 on a TV show.”

The lessons he learned: Be punctual, friendly, respectful and professional.

He also read up on the “NCIS” universe, something he knew about but wasn’t a big fan of.

In a pop quiz, Stowell correctly names all four of the franchise's spin-off shows, only stumbling when it comes to the rule of three of Gibbs' famous tenets: “Never believe what you're told.”

(He keeps the full list to read from time to time.)

Stowell posits that Gibbs' enduring appeal to audiences is due to his humanity.

“Gibbs doesn’t wear a cape. He just has to use his brain and his heart. I would argue that this makes him a superhero because it is real. This is something we can all achieve.”

“NCIS: Origins” isn’t just the procedural people know and love, Stowell says, even though it has all the crime-solving and fun banter of the franchise.

“It's a lot more like a 'True Detective' or, you know, a darker crime thriller. And that leads to some potentially awkward situations on set. A lot of times I find myself kind of in a dark corner.”

His co-stars and fellow NIS investigators (the C had not yet been added in 1991 when the series began) include Mariel Molino as Lala Dominguez and Caleb Foote's Randy.

It's Gibbs' first job since leaving the Marines. He has personal trauma and a reputation, but he also has the sniper focus and built-in lie detector needed to be an integral part of this Camp Pendleton-based mystery-solving team led by Kyle Schmid's charismatic Mike Franks.

“I just got to play this for the first time… the other night, where I'm looking at a character and I'm just like, 'You know, right?' And I just get to bury them in my eyes,” Stowell says with a laugh.

These eyes were enhanced with special contact lenses to achieve the correct “Mark Harmon Crystal Blue”.

“NCIS: Origins,” which premieres Monday on CBS, was filmed over three and a half months. During this time, Stowell recognized the parallels between himself and Gibbs, a character who distrusts technology, loves nature and spends years building a boat in his basement.

When he got the call about the role, Stowell was out of action in Vermont.

“I'm a very analog person, so I'm very comfortable in this 1991 world where conversations and relationships are important, not Siri and Alexa.”

Has Stowell learned to trust his gut and Gibbs' style?

“I read the pilot and immediately understood who this guy was. And so my gut feeling told me that I should be here from the beginning,” he says, close to tears.

“Something awakened in me, almost as if it was the character I’ve been waiting to play my whole life.”