Sarah Michelle Gellar Thinks She Manifested Her Role in Dexter Prequel as a ‘Big Fan’ of the Original (Exclusive)

Sarah Michelle Gellar’s role in Dexter: Original Sins is a long time coming.

The actress, 47, stars as Tanya Martin in the prequel series, which explores how the infamous serial killer originated by Michael C. Hall came to be the man viewers met in the 2006 series. She tells PEOPLE ahead of its premiere that manifesting might have had a little something to do with her casting.

“I actually think if somebody probably went back far enough in some of my interviews, I bet you at some point when someone asked me, ‘Is there a show or a movie that you wish you’d been a part of?’ I bet you that I have answered — more than once — ‘I would’ve loved to have been a guest character on Dexter,‘” she admits.

When her costar Patrick Gibson, who plays the 20-year-old version of the titular killer, suggests that she “manifested” this role, Gellar agrees. “I think I might have,” she says.

“Because I guarantee you I have said it, because I was such a big fan,” she continues.

“I always said, ‘Oh, it’s such a bummer that I missed my opportunity to be on that show,’ because they had such great character arcs, and then, you know what? Be careful what you wish for.”

When Gellar’s casting in the prequel series (which premieres Dec. 13) was announced in June, she wrote on Instagram that it would be a “bloody good ride,” and she can confirm it was.

“This cast gelled in a way that I’ve — you know, I’ve been doing this a very long time — I’ve never experienced.

Crediting the whole cast for arriving on set “with this sense of, ‘Let’s do this. Let’s kick butt, but let’s also go home,'” Gellar continues. “Nobody was late. Everybody knew their stuff. It was such the experience you hope to have.”

She also praises Gibson, 29, for his portrayal of young Dexter as she applauds him for playing the character so well despite being “the least creepy person you will ever meet.”

“He’s the sweetest, most charming [person],” she says of the Irish actor, who her character Tanya manages when he takes on a forensics internship at the Miami Metro Police Department. “So to see him up there, you have to understand that this is a character and he’s great at it, but it is a character.”

Dexter: Original Sins traces Dexter’s journey in 1991 Miami as he “transitions from student to avenging serial killer,” per the official synopsis. With the help of his dad Harry, played by Christian Slater, young Dexter adopts a code “designed to help him find and kill people who deserve to be eliminated from society without getting on law enforcement’s radar” — while also juggling an internship at the Miami Metro Police Department.

The 10-episode series also stars Patrick Dempsey, Christina Milian, Molly Brown, Reno Wilson, James Martinez and Alex Shimizu.

Dexter: Original Sins premieres Friday, Dec. 13 on Paramount+ with SHOWTIME Plan.