There was a moment in October 1977 when I watched Doctor Who at my grandparents' flat. The particular episode was part of ‘The Invisible Enemy’ (1–22 October 1977), in which the alien-infected Doctor was cloned and then miniaturised in order to be injected into himself. I bring this up in part to demonstrate the pitfalls of historical accounts, but also because the notion of the invisible enemy is an almost perfect description of one recurring trope within this book. The same episode dates the events of Paul Magrs's extraordinary Young Adult novel, Strange Boy (2002); an appendix to that novel explains what Doctor Who (23 November 1963–) is, along with Spangles, Battlestar Galactica (17 September 1978–29 April 1979) and other aspects of late 1970s popular culture. Anyone who lived through the period may find it hard to avoid feeling nostalgic, but also to resist a sense of camp. After a period of being shunned, the 1970s has returned with added postmodern irony, as popular culture draws upon the period with varying degrees of love and ridicule. In tracing this era, I do not want to indulge in nostalgia, to find my own foundation myth in my own autobiography or to be overly guided by where sf ended up in subsequent years.

I have adopted the metaphor of the Invisible Enemy to describe the ideological battlegrounds of the 1970s.