Last but not least, and arguably the most likely of all theories, is that Last Christmas will turn out to be Clara's final adventure with the Doctor. This is just speculation, of course, and with filming on Series 9 scheduled to begin in the new year, they're well and truly keeping us guessing about what the immediate future holds for the impossible girl. And Jenna Coleman is also remaining tight-lipped about her commitments to the series beyond December 2014, claiming "its much better if nobody knows. If you know Im in the next series then youll know how the story ends," she said in a recent interview. It's been rumoured she will be bidding adieu to life in the TARDIS for a while now, but will this Christmas be the Last Christmas she gives us her heart? Sorry. This started with a Wham! reference. It had to end with one, too. What are your predictions for the Christmas special? What does the title really mean? Have your say in the comments below.