The Doctor. In Order

Then: Hominid Prehistory   (Approximately the twelve million years before the Common Era)   Sweet Dreamer    Charity drabble, published 1993                           Doctor: Unbound Written by Stephen Gallagher. Arbitrary placement Might take place anywhere, with any incarnation of the Doctor. The Judgement of Isskar    Audio drama, released 2009        Doctor: 5 featuring the Ice Warriors, Grace technology, with the Cybermen (informative mention) Written by Simon Guerrier. Informed guess Takes place on Mars and Safeplace, some time between How Do You Kill Death and Descendence and Ascendence . The Sentinel    Comic story, published 1989                         ...