Dexter: Original Sin will tell the origin story of Dexter Morgan, as he hones his dark passenger using his adoptive father, Harry Morgan's code. James Remar played Harry in the original Dexter series, in a mixture of flashbacks and Dexter's ghostly visions, as the character died before the start of the original series. The prequel series will be initially set in 1991, and Christian Slater will play the younger and very much alive version of Harry Morgan, but it won't be long before his character dies if the timeline set out in Dexter is followed. Dexter: Original Sin could copy a vital plot point in relation to Harry's character from the original series and save it for a later season of the prequel show.