Double Doctor Who at rehearsals
David Tennant has stepped back in time to join Matt Smith at the first read through for the 50th anniversary Doctor Who special.
The two Time Lords joined Gavin And Stacey star Joanna Page and the Doctor's new assistant Jenna-Louise Coleman as they were given a sneak preview of the script for the 3D episode for the first time.
The BBC also revealed that as well as Joanna, former Doctor Who assistant Billie Piper and John Hurt will also be appearing in the 50th anniversary special.
Filming of the anniversary script will begin this week. It is rumoured the special will reunite all 11 actors who have played the Doctor, including footage of William Hartnell, Patrick Troughton and Jon Pertwee, who have died.
As well as Tennant, who left his role as Time Lord three years ago, it has been reported that Tom Baker, 79, Peter Davison, 61, Colin Baker, 69, Sylvester McCoy, 69, Paul McGann, 53, and Christopher Eccleston, 48, have been approached about the show.