Sarah Michelle Gellar Joins Cast of 'Dexter: Original Sin'

Sarah Michelle Gellar

Sarah Michelle Gellar is diving back into a world filled with secrets and bloody crimes. The "Buffy the Vampire Slayer" star appear in a guest role in the upcoming "Dexter" prequel series, "Dexter: Original Sin."

Gellar will portray Tanya Martin, the CSI Chief at the Miami Metro Police Department who is also Dexter Morgan's new boss. As previously announced, Patrick Gibson will play the serial killer in this prequel series.

"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," Nina L. Diaz, president of content and Chief Creative Officer for Showtime / MTV Entertainment Studios and Paramount Media Networks, said in a statement to press. "We're thrilled to have her return to the Showtime / MTV Entertainment Studios family and join the origin story of the Dexter franchise."

"Original Sin" takes place 15 years before the events of the critically acclaimed and beloved Showtime original and will chronicle America's favorite serial killer during his training years. The 10-episode thriller is set is 1991 Miami and will follow Dexter as he transitions from an average student to an above average killer guided by his father, who persuades him to use his bloodlust for good. Making this macabre education more complicated is the fact that Dexter's father works as a homicide detective, and Dexter is part of a forensics internship at the Miami Metro Police Department.

In addition to Gellar and Gibson, Christian Slater plays Harry Morgan, Patrick Dempsey plays Aaron Spencer, Molly Brown plays Debra Morgan, James Martinez plays Angel Batista, Christina Milian plays Maria LaGuerta, Alex Shimizu plays Vince Masuka and Reno Wilson plays Bobby Watt.

The Emmy-nominated Clyde Phillips, who is best known for his work on the original "Dexter" as well as "Nurse Jackie," will serve as the showrunner and executive producer of this spinoff. Other executive producers include Scott Reynolds ("Jessica Jones"), Michael C. Hall ("Dexter"), Mary Leah Sutton ("Resident Evil"), Tony Hernandez ("Emily in Paris") and Lilly Burns ("Russian Doll"). Robert Lloyd Lewis ("The Lincoln Lawyer") produces the series, and Michael Lehmann ("Heathers") serves as directing executive producer. The series is produced by Showtime Studios and Counterpart Studios.