Martin Donaldson is a World War I veteran living in London in the 1920s.
Biography
Martin Donaldson fought in World War I, consequently losing his leg in battle. After the conflict her went to live with his sister Kitty Donaldson.
In 1921 he met the Eighth Doctor and Liv Chenka when Kitty asked the Doctor to check up on him - thinking he was a medical doctor. This lead the Doctor to investigate an unstable time field around Martin, but not before Martin had taken Liv on a tour of London, during which they go to see a Buster Keaton film, go to a restaurant and visit the British Museum.
All through this Martin leaves items such as a diamond ring, and an alarm clock which aid the Doctor in evading capture by androids. When the androids have taken the TARDIS he saves the Doctor, Liv and Kitty by jumping onto a temporal grenade. This causes him to become stuck in a time loop, reliving the events of the previous day, hence the reason for him leaving items to assist the Doctor and Liv. (AUDIO: A Life In the Day )
Personality
Martin Donaldson is brave and resourceful. He likes comedy films and enjoys visiting the British Museum. As he tried to diffuse the grenade with the Doctor he confesses that he has fallen in love with Liv. (AUDIO: A Life in the Day)