Paramount+’s Dexter prequel cast keeps getting more impressive.

Emmy winner Sarah Michelle Gellar has signed onto Dexter: Original Sin, which follows a young Dexter Morgan (Patrick Gibson) as he becomes an avenging serial killer in Miami.

“Sarah Michelle Gellar is a pop culture icon who perfectly rounds out our best-in-class cast featuring Christian Slater and Patrick Dempsey among others,” said Nina L. Diaz, president of content and CCO, Showtime. “We’re thrilled to have her return to the Showtime/MTV Entertainment Studios family and join the origin story of the Dexter franchise.”

Gellar will have special guest star role as Tanya Martin, the CSI Chief at the Miami Metro Police Department and Dexter Morgan’s new boss.

Gellar is, of course, known for the beloved The WB series Buffy the Vampire Slayer, as well as her work in films such as Cruel Intentions, I Know What You Did Last Summer, The Grudge and Scooby Doo. She recently starred in and executive produced the Paramount+ genre series Wolf Pack.

Here’s the official description of the Dexter prequel: “Set in 1991 Miami, Dexter: Original Sin follows Dexter as he transitions from student to avenging serial killer. When his bloodthirsty urges can’t be ignored any longer, Dexter must learn to channel his inner darkness. With the guidance of his father, Harry (Slater), he 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. This is a particular challenge for young Dexter as he begins a forensics internship at the Miami Metro Police Department.”

Clyde Phillips has returned to the franchise as showrunner after having previously helmed some of the original series’ best seasons.

Dempsey plays Aaron Spencer, while Molly Brown is Dexter’s sister Debra Morgan. In addition, the show has cast James Martinez as Angel Batista, Christina Milian as Maria LaGuerta, Alex Shimizu as Vince Masuka and Reno Wilson as Bobby Watt.