Official! What happens at Christmas!

An extract from Russel T Davies book, this explains a little about the christmas special, and also means that the episode could be called The One Doctor. Here it is!

"The Doctor arrives, hears a damsel in distress," says Russell. "The Doctor steps forward to save her... when this other man [to be played by David Morrissey] swings in, dashing, brilliant, amazing, clever, witty, saves the day. The Doctor says, 'Who are you?' The man says, 'I'm the Doctor!' Good scene. The Doctor becomes his companion. I like that. Sweet. There will be a beautiful woman too, of course, but really it's the Doctor paired with a new Doctor."