Billie Piper
The advent of the show's 50th anniversary in November 2013 meant that instead of starting to film an 8th series, the BBC started work on a feature-length special, to be transmitted on 23 November 2013, the precise date of the show's 50th anniversary. As well as being made in 3D for presentation at selected cinemas, the episode was also announced to be co-starring David Tennant and Billie Piper, reprising their roles of the Tenth Doctor and Rose, though ultimately Billie Piper played The Moment, a Gallifreyan Weapon that took the form of Rose.