The medical humanities are becoming increasingly important as their first wave is interrogated by a critical approach that aims to uncover the wider possibilities of the field. In conversation with this debate, this volume explores the ways in which science fiction studies can contribute to such discussions. Science fiction challenges techno-optimism and offers a non-realist avenue for the expression of illness experience. Science fiction also estranges its readers from their societies and the medical possibilities inherent in those societies, inviting consideration of how medicine may be complicit with, or opposed to, other structures of power. By engaging these concerns, this Companion volume offers a unique viewpoint on the power of the future to shape the present.