Sarah Michelle Gellar has joined the cast of Showtime’s ‘Dexter’ prequel series, Dexter: Original Sin. Deadline reported that Gellar, 47, will guest star as Tanya Martin, the CSI Chief at the Miami Metro Police Department and Dexter Morgan’s new boss, in the Paramount+ with Showtime series.

Dexter: Original Sin is a prequel to the Showtime series Dexter, which had an eight-season run from 2006 to 2013. Patrick Gibson will play a young Dexter Morgan, the vigilante serial killer portrayed by Michael C. Hall in the original show. Gellar joins Gibson and previously announced stars Christian Slater (Dexter’s adoptive father, Harry) and Molly Brown (Dexter’s sister Debra). Other cast members include Patrick Dempsey, James Martinez, Christina Milian, Alex Shimizu and Reno Wilson.

The official description of Dexter: Original Sin reads: “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.”

Nina L. Diaz, president of content and CCO, Showtime, said: “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. We’re thrilled to have her return to the Showtime/MTV Entertainment Studios family and join the origin story of the Dexter franchise.”

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