One of the earliest science fiction movies - Fritz Lang's 1927 masterpiece Metropolis - was made without CGI or the other tricks of modern cinema. Yet it still has the power to astonish.Since then we have experienced ever more convincing representations of the impossible. Forbidden Planet, Solaris, 2001, Star Wars and Blade Runner - the appetite for fantasy seems endless, and filmmakers have responded with some of the most thrilling and immersive experiences in cinema.In this episode Mark will explore these brave new worlds and examine the technical tricks and storytelling devices at the heart of the best examples of the genre. And he'll show how, throughout its history, science fiction cinema has tapped deeply into our emotions and abiding preoccupations.