‘Game of Thrones’ star Aidan Gillen talks leaving HBO series, suiting up for ‘Project Blue Book’

Aidan Gillen isn’t mourning the loss of Petyr “Littlefinger” Baelish.

The 50-year-old Irish actor, who starred as the self-made lord and schemer in HBO’s “Game of Thrones” from 2011 until 2017, told Fox News he’s not sorry to see his character go.

Fans of the fantasy drama still remember when Baelish met his end on the Season 7 finale. After his death sentence for treason and murder was pronounced by former ward Sansa Stark (Sophie Turner), her sister Arya (Maisie Williams) carried out the execution by slitting his throat.

“It was brilliant to be part of ‘Game of Thrones’ for the amount of time I was, which was seven seasons,” said Gillen. “But it’s also nice to be done with that, walk away and find a new suit to put on. For me anyway, it’s always what’s happening right now. That’s the exciting thing. And that’s always what I’m doing. And everything else takes place in the background.”

Aidan Gillen and Sophie Turner attend the premiere of HBO's

Aidan Gillen and Sophie Turner attend the premiere of HBO’s “Game Of Thrones” Season 6 at TCL Chinese Theatre on April 10, 2016 in Hollywood, California. (Getty)

And Gillen has already moved on from the master manipulator. In fact, he’s decided to ditch dragons to search for alien life.

Gillen is currently starring in a new mystery series on the History Channel titled “Project Blue Book.” The show, which is based on a true story, explores U.S. Air Force-sponsored investigations into UFO-related phenomenon from 1947-70. Gillen plays Dr. Allen Hynek, an astrophysicist who serves as a consultant to the Air Force project where he assesses reports on UFOs.

Hynek is credited with coining the phrase “close encounters of the third kind” to describe humans meeting aliens from outer space. He later served as technical adviser to the 1977 Steven Spielberg film that had the same title.

Gillen said he didn’t hesitate to take on the role.

Aidan Gillen as Dr. Hynek. — History Channel

Aidan Gillen as Dr. Hynek. — History Channel

“I’ve been kind of fascinated with this subject since an early age,” he explained. “So, to be able to drop into the life of the actual guy who inspired Spielberg to make one of my favorite films, the first film I ever went to see on my own in the cinema, ‘Close Encounters of a Third Kind,’ was a no-brainer.”

The real-life Hynek passed away in 1986 at age 75 of a malignant brain tumor. However, Gillen shared his sons were supportive of the show and served as advisers.

“For my own part, I guess there is quite a lot of material there,” said Gillen. “Hynek had written books and a lot of onscreen stuff that was available to watch. Of course, I read all that I could find and glean from that. But we also were lucky enough to be able to have some access to the Hynek family, in particular, Paul and Joel, two of his sons, who would share more personal insights and little things like family photographs, which weren’t little to me.

“It was really great to have them involved. My big thing was I just wanted to know what kind of a person he was outside of the public eye, off-camera — as a family man. Because I reckoned that was what it was all rooted in. His work and his passions were rooted in the love of family and earthly things.”

On the set of

On the set of “Close Encounters of the Third Kind.” — Getty

Gillen added that each episode of “Project Blue Book” focuses on an actual case that was investigated. ETOnline previously reported that over 12,000 sightings were reported to Project Blue Book during its time, and show creator David O’Leary intended to make use of as many as he could — or at least the “juiciest.”

“To work in a genre that’s primarily associated with fantasy, or make-believe, or the imagination, and to have each of your scripts based on a real case that was reported by multiple people and investigated by the government is unique,” said Gillen. “Sci-fact as opposed to science fiction.”

And Gillen wasn’t the only one who meticulously studied for his new role. Gillen’s co-star Michael Malarkey of “The Vampire Diaries” fame said he happily dived into the role of Captain Michael Quinn, who is loosely based on Edward J. Ruppelt, the Air Force officer involved with Project Blue Book.

“… I have somebody I know who’s in the Air Force who was a great source for me,” the 35-year-old British-American actor told Fox News. “And also, I grew up very close to [the] Wright-Patterson Air Force base, which is where the Blue Book headquarters was, which is a weird little full circle for me personally.

The cast of

The cast of “Project Blue Book.” — History Channel

“I went into Wright-Patterson to do a lot of my preliminary research, I even did some flying lessons and flew a plane myself. … I felt it was very important for me to get a sense of the etiquette and where their heart sits on things.”

Gillen is aware he may never escape his “Game of Thrones” past. But these days, he’s looking forward to his future and the great beyond.

“I’m taking on characters all the time,” he said. “It always feels good, whatever the latest one is, that’s where it’s happening, you know? … I know the ‘Game of Thrones’ thing is still very current for me and I talk to people about it every day, but I’m Hynek now.”

“Project Blue Blue” premieres Tuesday, Jan. 8 at 10 p.m.