Actress Jessica Raine is to play the woman who brought Dr Who to life, in a one-off drama, marking the sci-fi series' 50th anniversary.
The Call The Midwife star will play Verity Lambert, in the 90-minute BBC2 special, An Adventure In Space And Time.
Harry Potter star David Bradley will take on the role of the first doctor, William Hartnell.
Speaking about the role, he said: "William Hartnell was one of the finest character actors of our time and as a fan I want to make sure that I do him justice. I'm so looking forward to getting started."
The anniversary special will be penned by Dr Who writer Mark Gatiss, and Executive Produced by The Doctor's current show runner Steven Moffat.