25 February 1997: death of Arthur Hewlett, who played rebel scientist Kalmar in State of Decay (Fourth Doctor, 1980) and doomed passenger Kimber in Terror of the Vervoids (Sixth Doctor, 1986).
25 February 1967: broadcast of third episode of The Moonbase. The Cybermen take over the base, but Polly works out a way of killing them with nail varnish remover.
25 February 1978: broadcast of fourth episode of The Invasion of Time. Leela and the Shobogans combine with the Doctor to destroy the Vardans; but the Sontarans have landed.