CASTING SPOILERS AHEAD

If, like us, you've been scurrying around the Internet to try and find the best quality version of the trailer to The End Of Time that was shown at the San Diego Comic-Con a few days back, then the news we're about to tell you will hardly come as a surprise. For the BBC has now officially confirmed one of the worst kept secrets about David Tennant's final two special episodes of Doctor Who this Christmas. And that's that John Simm will indeed be returning as The Master.

From the trailer, that's not been officially released in a useable version yet we're afraid, we can see that Simm's hair colour has gone light, and that Tennant's final episodes will also see a collection of faces from the past few years of Who returning. The highlight for us isn't Donna Noble popping back up, but the return of Bernard Cribbins as Wilf.

Also returning for the big send off is the character of Lucy Saxon, played by Alexandra Moen, who was, of course, The Master's wife when he last appeared at the end of season three (although she did shoot him, so there are some loose ends to tie up there). And we're sure we've spotted the Ood in the midst of the trailer, too.

Finally, The End Of Time trailer has been narrated by Mr Timothy Dalton, who will be appearing in the specials as another Time Lord, we understand. James Bond, eh? He gets everywhere.

We can't attach the trailer to this post, but the best version we've found of it thus far is right here.