The Dexter universe continues to grow. Fresh off the heels of a sequel series, the hit Showtime series is gearing up for a prequel, titled Dexter: Original Sin, that will explore the early days of the titular character’s life. As the name suggests, it dives into the start of the character’s urge to kill, and it takes place 15 years before the events of the original series. Original Sin will detail how Harry, Dexter’s dad, helped him adapt his code of only killing people who deserve it. It will also include new original characters, with Sarah Michelle Gellar and Patrick Dempsey both playing big roles in Original Sin as revealed in newly-released images.

Dexter will no longer be played by Michael C. Hall, something to be expected considering it’s a prequel set more than a decade in the past, but he is still narrating it. Stepping into the future serial killer’s shoes is Patrick Gibson of Netflix’s Shadow and Bone fame. Joining him are some familiar faces to avid TV viewers, Sarah Michelle Gellar and Patrick Dempsey, who are both playing big roles in the upcoming prequel. Thanks to Entertainment Weekly, the first look at what the two characters will look like in the series has been unveiled. Fans are in for a shock if the last time they’ve seen Dempsey is in Grey’s Anatomy.

First Look at Patrick Dempsey & Sarah Michelle Gellar in Dexter: Original Sin

Dempsey is taking on the role of Captain Aaron Spencer of the Miami Metro Police’s homicide division. Gellar is portraying Tanya Martin, the CSI Chief. This is far from Dempsey’s first role as a member of law enforcement, as he played a detective in the Scream series and a sheriff in 2023’s Thanksgiving. The series is set in the 1990s, so Gellar and Dempsey get to play around with different hairstyles and looks than they would otherwise get to wear today. The mustache Dempsey is sporting is completely real, although it was never meant to be part of the character.

“I have to tell you, it was discovered accidentally. I was on holiday and I hadn’t shaved in a while. I shaved my beard off because we were getting ready to come home and I kept the mustache going, thinking, ‘Maybe I should do this,’ because I was looking at a lot of vintage training videos of Miami police in the ’70s and they all had mustaches. And then my hair was long and I slicked it back and I sent the picture to makeup and hair and they loved the idea, and that’s how it started.”

Related Was Dexter Inspired by a True Story? Dexter Morgan from Dexter is one of those characters fans love, but don’t feel good about it; and fans wonder if he was based on a real person.

As for Gellar, she says her character takes on a more comic relief role. Through this comedy, she inadvertently teaches Dexter a lot of what it takes to become a successful killer.

“It’s fun to sort of inadvertently be the character that teaches Dexter everything that he needs to know to really be a good serial killer, but all the while not knowing that you’re doing it.”

Neither of these characters appear in the original Dexter series, so that could potentially be bad news for them. Of course, there’s a chance they will simply move away or take jobs elsewhere instead of dying. Whatever the case is, viewers won’t have to wait long to find out. For people looking for even more Dexter, they can stay tuned for Dexter: Resurrection, a continuation of the character following the New Blood sequel series that was announced at the 2024 San Diego Comic-Con.

Dexter: Original Sin
releases on Paramount+ in December.