Doctor Who S3 Christmas Special

Continuing off of a hook left in the finale of season 2, Catherine Tate as Donna, a bride to be, randomly disappears from her wedding and into the TARDIS.  The Doctor tries to get her back to her wedding, but then they miss it, so decide to go to the reception instead.  The plastic Santa robots from the previous Christmas special return, but this time they're controlled by a Raknos (sp?) who wants to reawaken her children.  Eventually (spoiler!) it comes out that Donna's fiance has been poisoning her for the last six months with this old sort of energy that the Raknos needs to reawaken her children.  At the end of the episode, the Doctor offers to let Donna come, but she doesn't want to.