Doctor Who: The end of time. Christmas eve, 6pm, BBC1W & BBC HD.

The TARDIS will be completely destroyed during this Christmas's Doctor Who two-part special. 

David Tennant's Doctor dies in mortal combat with The Master, played by the marvelous John Simm, now with blond hair. A new TARDIS regenerates, looks the same outside, but is new - and massive on the inside. It takes up all of the set previously occupied the Torchwood Hub in Upper Boat.

But where does it get its regeneration energy from? Could it be provided by Captain Jack, originally made immortal by vortex plasma from the TARDIS? 

Does Jack sacrifice himself to save the Universe? 

John Barrowman has said Jack's back in the new Torchwood Series 4, said to be filming from January, but could this be a bluff? Has Russell T. Davies decided to finish Jack off, to make way for a brand new Torchwood cast

Jack's death, though unpalatable, makes sense - after all, he was made immortal when Rose Tyler brought him back to life after he was exterminated by a Dalek. She used energy from the Tardis's time vortex to resurrect him. This would be the perfect form of energy to restore a 'dying' Tardis... but would it cost Jack his immortality - and his life?

Watch... see... weep!