The way I read it is this, with the Timlords gone, the rules of the universe are a bit looser so we get all sorts of unusual anomalies. But maybe they are all going somewhere.

As I discussed with a friend last night, the fact that Rose was avoiding the Doctor in person and ultimately got Donna to invoke ‘Bad Wolf’ (which got the cloister bell to go off) is also significant and maybe connected. Why did Rose know about the universal barriers breaking down and not the Doctor? Why was she shadowing him, with the occasional transmissions to him being blocked? Has she been trying to awaken Donna all along?

For that matter why has there been this recurring theme with changing the timeline into a form without the Doctor? We don’t know who was really behind the attack on Donna in ‘Turn Left’ or what their purpose really was. Davros? I doubt it. Particularly if RTD really is riffing DC’s Crisis on Infinite Earths’, the real ‘Darkness’ would have to be far more substantial. Someone along the lines of a ‘Dark Rassilon’.

As far as Donna goes, the speculation I’ve seen this week is starting to make sense out of her. ‘I’m just a temp’ is a clue – a huge one. She’ll be some form of ‘key’ (like Dawn in ‘Buffy’, which RTD constantly swipes from), created by the Doctor, the Master, the Time Lords or another player for the Bad Wolf scenario. It seems likely she’ll sacrifice herself upon realising this to lock Davros into the Medusa Cascade, and Ten will be so outraged that he’ll do what Caan did and go back and remaster his timeline to prevent her death. Jack can then wipe her mind with Torchwood technology, allowing a happy but non-superheroic future for Donna.

What do other people think? It would join a few more dots, but not explain definitively why the ‘Doctor-split’ happens. Maybe that really is for the Master’s benefit, and Donna, as his creation, turns on him?