Just watched it myself. I normally can see stuff like this a mile away, but that ending escaped me. Crazy.
So, for Season 5, let me just ask: How, exactly, do you top an ending AND a serial killer like that? Almost seems like they've set up an ending so twisty and wacky that they'll be hard pressed to write out of it.
I guess now it's official that Season 3 (in my book) is the least of the series, even though I still like it a lot. Me and a friend had a running joke with Jimmy Smits, that every time he got thwarted he would look up at the sky, shake his fist, and yell, "Dex-TERRRRRRRR!" I miss his character.