Dr Alison Kolitz was a mineralogist. She was stationed on Mercury as part of the Sunwatcher project.
One day while patrolling the dark side of the planet, she encountered a disorientated Mercurial and brought it into the base. When it seemed to be attacking other scientists on the base, she sent out a distress signal and assumed that the Second Doctor, Jamie McCrimmon and Zoe Heriot arrived in answer to the signal. She helped them make contact with the Mercurials. (PROSE: Mercury)