The role to be tackled by the former 'Eli Stone' lead is still unknown but it would be quite major judging from the number of episodes he's in.
Beside Julia Stiles, "Dexter" will also get a visit from Jonny Lee Miller. This would be the first American TV stint for the English actor, who was once married to Angelina Jolie, after "Eli Stone" wrapped up last year.
Little is known about his role but it looks like the fifth season of "Dexter" will be playing the "mysterious" card. According to Variety, Miller would be "a mysterious man" who is involved with equally mysterious character played by Stiles. He is slated to appear in a multi-episode arc.
Production of the fifth season is underway for a Fall premiere. Julie Benz is confirmed to make a return to the series although her character was killed at the end of season 4. Shawn Hatosy and Maria Doyle Kennedy are the new additions. The former is to take the role of Dexter's nanny.