This Christmas, the first installment of Doctor Who: The End of Time will be screened in the UK. Featuring the well publicized demise of the tenth Doctor, David Tennant and the birth of a new, younger model in Matt Smith, the two-parter is sure to be a ratings winner.

But what do we actually know about Tennant’s swansong? Four knocks will signal his doom, the Ood have also predicted his demise and of course The Master will be making his long awaited comeback also, but still, actual details about the plot remain scarce.

Also bowing out this year is Russel T. Davies as the show’s writer and executive producer, so expect all bets to be off in the first episode, to be screened on Dec 25th. Speaking to Wales Online, Davies was clear that the story would be kept under wraps until the big day, and that fans should appreciate that fact:

“We do like keeping secrets. You should always watch it without knowing what’s going to happen and watch it unfold, brand new in front of you.”

“If you want to go online and look for all the spoilers then go ahead, but I know for a fact you are depriving yourself of enjoyment, which I think says a lot about the online experience. It ruins it when you know too much.”

So with little to go on in the way of plot spoilers, how about those images? Released today by the BBC, we have pictures of The Master, gagged and bound and flanked by armed guards. However, knowing The Master, one would assume that it’s all part of a far grander plan.