via Mark Gatiss on Twitter: David Bradley as William Hartnell, Gatiss as Jon Pertwee, and Reece Shearsmith as Patrick Troughton, from "An Adventure in Space and Time" | http://twitter.com/Markgatiss/status/404176042908078080 | Excuse the liberty (hall)! #SaveTheDay on Twitpic
Mark Gatiss also played the voice of an Alternate Universe Master in the Big Finish Audio Series: Doctor Who - Unbound - 2. Sympathy for the Devil. David Tennant has a role in the audio as Colonel Brimmicombe-Wood of U.N.I.T. David Warner played the Doctor and Nicholas Courtney reprised his role as the Brigadier.