The baddies and their mutant cousins the Cybershades-who are led by CyberKing-creep up on a vicar (Jason Morell) during a funeral in Victorian London.
Star David Tennant must team up with another Doctor, played by David Morrissey, to have any chance of defeating them.
But we can reveal Morrissey, 43-who is bookies' favourite to become the next Who when Tennant leaves-will NOT be the new Doctor.
Instead, Gavin and Stacey star Mathew Horne, 30, is being lined up as a possibility, along with Mighty Boosh actor Noel Fielding, 35, and Trainspotting's Robert Carlyle, 47.
Actors James Nesbitt and Rhys Ifans are outsiders for the role.
Last night a BBC source said: "A decision is imminent. But David Morrissey is definitely out. When you see the Christmas special it's clear he is not in the running to come back permanently as the Doctor."

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This article has 1 comment
well Robert Carlyle is out as he has signed for stargate universe, and as for Noel Fielding are you kidding me he is defo not Doctor material i could however see Mathew Horne in the role
By Ian.. Posted December 16 2008 at 5:21 PM.