NCIS star Mark Harmon has confirmed that he will release his first book this year, two years after leaving the hit police procedural.
The actor, who played Leroy Jethro Gibbs on the CBS show, will release the historical non-fiction book Ghosts of Honolulu: A Japanese Spy, a Japanese American Spy Hunter, and the Untold Story of Pearl Harbor on November 14.
Written alongside former Special Agent Leon Carroll Jr, the book will tell the true story of Japanese-American spy Douglas Wada. The intelligence officer posed as a local reporter to gather information on the Japanese on behalf of the US Navy following the tragic events of Pearl Harbour.
Related: NCIS star Katrina Law debuts hot-pink hair transformation
Speaking to PEOPLE, Harmon explained why he felt it important to delve into the work of the Naval Criminal Investigative Service in his book. “I’ve always thought you can learn from history. Things tend to repeat themselves,” he said.
“This is the first story [leading] to the birth of what became [the real] NCIS. These agents are really [of] a different breed. I hope that there’s a story revealed here that you don’t know. It was important work they were doing, and no one knew about it.”
The actor also revealed how integral co-writer Carroll Jr was to the writing process. The pair formed a longstanding friendship on NCIS when the former real-life agent joined the show as a technical advisor.
Related: NCIS creator isn’t surprised show never got an Emmy nod
“I was always asking him about the right way to do something or the way he would do something. There wasn’t any interrogation I was ever part of on this show that I didn’t talk to him about,” Harmon said. “So when this idea came to me, I wanted it to be real. I said I wouldn’t touch this without him.”
Harmon starred in the hit show for 19 seasons before departing in 2021. For his final scene, Special Agent Gibbs was seen winding down in Alaska on a fishing boat after finishing a big case.
Much like his NCIS character, Harmon feels lucky to have more freedom in this stage of life. “I’ve got time to do whatever I want to,” he said. “I can plan a dinner with the boys [his sons], we can take a trip. I’m so fortunate — I don’t ever wake up not thinking that.”
