1. Bad Wolf
Of course, I always save my most-likely one for last. When Rose stepped out of the TARDIS and declared herself the Bad Wolf, she spread out the message Bad Wolf throughout the universe. In the episode Parting of The Ways, we think that this is only true to send out a message to her throughout series one. This is the case until series four, when Bad Wolf comes back when the Doctors in trouble before Journeys End. They brought back it at the end of the series four, so I find it really inevitable that theyre going to bring it back in this episode. In fact, it could be her as the BAD WOLF. If she was right in saying that she could see everything that ever was, all that can be, and all that could be, she would have seen this coming, wouldnt she? So while she was helping the Doctor defeat the Daleks on Satellite One, a part of her was sent to John Hurt to help him throughout the journey of the Fiftieth. This is most likely because Bad Wolf has been such a big thing in the new series, so it would be smart to bring it back as a warning message, in an episode where the Doctor is in danger. Especially with the fact that she looks possessed by someone in the episode barring a villain possessing her she could be possessed by ultra-powerful counterpart, who's witnessed the havoc the 8.5 regeneration will cause. These are the three most sane theories I could think of as to why Roses eyes have what looks like the Time Vortex in them. Do you have an idea? Why do you think Roses eyes are yellow? Feel free to comment below!