Dexter: Original Sin’ casts Patrick Gibson, Christian Slater, and Molly Brown

Dexter: Original Sin’s cast has been announced.

Dexter: Original Sin, the prequel series to the hit show Dexter, has announced its main cast. Patrick Gibson, known for his role in Shadow and Bone, will play a young Dexter Morgan. Christian Slater (Mr. Robot) is set to portray Dexter’s adoptive father, Harry Morgan, and Molly Brown (Senior Year) will play Dexter’s younger sister, Debra Morgan. The series will be available on Paramount+ with Showtime.

The original Dexter series, which aired for eight seasons on Showtime, starred Michael C. Hall as Dexter Morgan, a blood spatter analyst with a double life as a serial killer. James Remar and Jennifer Carpenter originally played Harry and Debra Morgan, respectively.

Clyde Phillips, a veteran of the original Dexter series, returns as showrunner and executive producer for the 10-episode prequel. Set in 1991 Miami, Dexter: Original Sin follows a young Dexter as he transitions from a student to a serial killer in training. His adoptive father, Harry, becomes his confidant, teaching him a code to target and eliminate those who deserve to die while evading law enforcement. Dexter also starts a forensics internship at the Miami Metro Police Department, adding complexity to his secret life.

“Dexter: Original Sin follows Dexter in 1991 Miami, as a student transitioning into a serial killer in training. When his bloodthirsty urges can no longer be ignored, Dexter finds solace and understanding in Harry. As his only confidant, he teaches Dexter a Code that’s designed to help him find and kill people who deserve to die—all while avoiding getting caught by law enforcement,” the official logline states.

The series is produced by Showtime Studios and Counterpart Studios.

Dexter: Original Sin was initially announced in February 2023, and it will explore Dexter's early years and the development of his lethal code under Harry's guidance.