Few movies of recent times have caught and shocked our imagination as the Alien cinematic quartet and the quest of Sigourney Weaver's Flight Lieutenant Ellen Ripley. In this gripping and lucidly written book, Mulhall shows why these films fascinate us, by showing that they are compelling examples of philosophy in action.

Bringing a philosopher's eye to cinema, he argues that the Alien films take us deep into the question of what it is to be human. By developing the sexual significance of the aliens themselves and of Ripley's resistance to them, these films explore the relation of human identity to the body, in the context of a hyper-Darwinian universe which both sharpens and subverts the distinction between the natural and the technological, and which pits the hope of redemption against nihilism.

The book also considers the nature of "sequeldom" in contemporary cinema. What is the relation between each Alien movie's distinctive plot and the overarching narrative of the Alien universe? How does the work of each director who has contributed to the series relate to the themes of their other films, such as Ridley Scott's Blade Runner, James Cameron's Terminator and David Fincher's Se7en?