Congratulations to Stephen Moffat for engaging all us Whovians with your crack. The "Crack" crack. Surfed a bit and found a lot of speculation on what Crack means, that Prisoner Zero prophecy, etc. Davies' foreshadowing was too subtle, or else his ideas for season closers hadn't gelled yet. But Moffat shoves it at you and gets you thinking, and before you know it, you are running frame by frame, watching episodes a couple of times to see anything you missed, and arguing with fellow geeks in the forums.