Ronald Moore has promised he'll reveal the identity of the final Cylon before the end of the series. But here's what we know so far:

-- The final Cylon is familiar to Number Three. She recognizes it during her vision in the Temple of Jupiter. She says "You ... forgive me ... I had no idea ..." and tells Baltar that he was "right," before collapsing.

-- In the extended cut of "Razor," the hybrid claims that the "fifth [Cylon], still in shadow, will claw toward the light, hungering for redemption that will only come in the howl of terrible suffering."

-- In an interview with Entertainment Weekly, Moore claims that the final Cylon is not on display in the promotional poster for the fourth season. Since the poster contains almost every major character in the "Galactica" universe, including Starbuck, Adama, Apollo and Roslin, this leaves us with either an as-yet-unknown Cylon character or a supporting character Cylon -- or Moore was leading us on.