Really exciting news hit the press today. Reports say that John Lithgow will be joining the cast of Dexter! Lithgow will appear in all 12 episodes of the show’s upcoming fourth season, playing Walter Simmons.

For more info about his character read on after the cut, but beware of spoilers.

Simmons is described as an unassuming, mild-mannered suburbanite who has been living a duel life as one of America’s most prolific and deadliest serial killers, dubbed the “Trinity Killer” because of his proclivity to kill in threes. He relocates to Miami after being tracked by F.B.I. Special Agent Frank Lundy (Keith Carradine) where Dexter Morgan is brought on to assist in the investigation and becomes fascinated with “Trinity’s” skills.

Season four of Dexter premieres September 27.