A is for... Allison

Surname Williams, she was assistant to Professor Rachel Jensen, from Cambridge University, who was seconded to a special army unit led by Group Captain Gilmore. In late 1963, Allison and Jensen were called upon to help investigate strange radio signals emanating from the Shoreditch district of London - the Coal Hill area to be precise. The Seventh Doctor and Ace met her whilst she was monitoring the signals in the back of a van, outside Coal Hill School.
The signals proved to be the work of the Daleks, who were active in the area as they searched for the Hand of Omega, hidden here some time before by the First Doctor. Allison and her boss had to come to terms not only with alien creatures, but two rival factions of Daleks, who had the potential to destroy all life on the planet. She stood alongside the Doctor when he brought the conflict to a close by goading Davros into activating the Hand prematurely, destroying Skaro and his mothership.

Played by Karen Gledhill. Appearances: Remembrance of the Daleks (1988).

• Karen has gone on to reprise the role of Allison for the Big Finish Counter-Measures series of audios, which reunites her with Pamela Salem (Jensen) and Simon Williams (Gilmore).