David Bradley, Brian Cox, Jessica Raine and Sacha Dhawan are all set to star in the BBC and BBC America telemovie "An Adventure in Space and Time".
The project deals with the creation of the long-running sci-fi series "Doctor Who" and is being done in time for the show's 50th anniversary later this year.
Bradley ("Harry Potter") is set to play the first ever Doctor, the iconic William Hartnell. Cox will play the BBC's Head of Drama Sydney Newman, credited with the creation of the show.
Raine ("Call the Midwife") will play famed producer Verity Lambert, and Dhawan ("The History Boys") will play Waris Hussein, the director of the first ever episode "An Unearthly Child".
Mark Gatiss ("Sherlock", "Doctor Who") penned the telemovie and will executive produce alongside 'Who' producers Steven Moffat and Caroline Skinner. Terry McDonough ("Breaking Bad", "The Street") will direct.