Dexter is going to have to do something really impressive to top the outstanding third season of the show, but it's taken a major step in the right direction with the first major casting announcement for season four.

For it's now been revealed over at Entertainment Weekly that there's going to be a new character crossing swords with Dexter, and he's going to be played by none other than John Lithgow.

Lithgow has form playing villains, of course, with his turns in 90s flicks Cliffhanger and Raising Cain etched in the memory. But in Dexter he's going to be playing Walter Simmons, who under the surface turns out to be a deadly serial killer by the name of the Trinity Killer (he always kills in threes, apparently).

Simmons, who has evaded capture for three decades, moves to Miami, and that puts him firmly on the radar of Dexter. We can't wait to see how it pans out, as right now, it sounds one of the finest pieces of casting news we've heard in some time...

Dexter returns to US TV screens in September.

Entertainment Weekly