The Sentinels of the New Dawn
Dr Teri Billington was a good friend of Liz Shaw
Billington and Liz Shaw were both research fellows at the University of Cambridge. She remained at the university as a PhD student in the Department of Applied Mathematics and Theoretical Physics, with Liz working under her.
In the early 1970s, Billington was working on an unofficial particle acceleration project at the astrophysics laboratory which she was funding with her own money. She constructed a particle accelerator with which she planned to achieve time dilation and, thus, time travel. Liz was concerned with her work and summoned the Third Doctor to the university to investigate. After being kidnapped by the Sentinels of the New Dawn and being taken to 2014, Liz returned and disassembled the accelerator, telling Billington that she had concerns about the implications of time travel. She neglected to properly debrief UNIT on New Dawn, wanting to keep Billington from being placed under surveillance.
Billington believed that Liz had acted out of professional jealousy and never spoke to her again, being unable to again raise the funds to rebuild the accelerator. She suffered a fatal stroke three years and eight months afterwards, having served as chair of the Council for Mathematical Sciences for only one month and one day. Liz succeeded her as chair. (The Sentinels of the New Dawn)