Matt Smith's swansong episode as Doctor Who had to be reritten after he injured his leg, according to reports. The injury was written into the script of the Christmas Day show so fans will see the timelord lose a leg after a battle with the weeping angels.
The Sun reported that fans will see the doctor grow old fighting cybermen and daleks after being drawn back to a planet called Trenzalore by the sound of a bell.
Smith, who is replaced by Peter Capaldi in the Christmas Day episode, said he was excited about his final appearance.
The outgoing Doctor Who, Matt Smith, welcomed the decision to cast Peter Capaldi.
In a pre-recorded message he said: "I just want to wish my successor all the best and just say good luck and good on you for getting it, because I know he is both a huge fan of the show and a really nice guy.
"The casting of it made me really excited genuinely, and as a fan I think it's a really canny choice, so good luck mate, it's going to be a thrill."
Matt Smith is leaving Doctor Who and will bow out in the Christmas special when he will be replaced by a new incarnation of the Time Lord, the BBC has announced.
Smith, who has been in the role since 2010, said it had been "an honour" to play the role.
The actor said: "Doctor Who has been the most brilliant experience for me as an actor and a bloke, and that largely is down to the cast, crew and fans of the show.
"I'm incredibly grateful to all the cast and crew who work tirelessly every day, to realise all the elements of the show and deliver Doctor Who to the audience. Many of them have become good friends and I'm incredibly proud of what we have achieved over the last four years".
The man who first brought Doctor Who to British screens has criticised the current series for being too sexy.
Waris Hussein, who directed the first episodes of the long-running science fiction show when it began in 1963, said he has been unimpressed by Jenna-Louise Coleman's character's romantic relationship with Matt Smith's version of the Time Lord.
"There is an element now, and I know we're living in a different era, of sexuality that has crept in," he told BBC Radio 4's The Reunion.
"The intriguing thing about the original person was that you never quite knew about him and there was a mystery and an unavailability about him," he added. "Now we've just had a recent rebirth and another girl has joined us, a companion, she actually snogged him."
Doctor Who star Matt Smith is introducing poetry to a new generation. The actor is to narrate a children's TV show designed to encourage the joys of literacy in youngsters.
Other names recruited for readings on Disney Junior UK's A Poem Is include Britain's Got Talent judge David Walliams and Downton Abbey's Michelle Dockery. Smith will read Jack Prelutsky's Once They All Believed In Dragons.
He will take part in the second series of A Poem Is, which starts on April 30, along with Twenty Twelve star Jessica Hynes and veteran actor Richard Briers. Their words will be set to scenes from classic animations.