Stephen Hawking is both subject and guide in this Horizon special, which sets his personal story against the physics he spent his career pursuing. The film traces his early work on the laws of thermodynamics through to his later arguments about black holes, the origin of time, and the shape of the cosmos, using interviews with the physicist alongside colleagues who worked through the ideas with him. Visual demonstrations stand in for the mathematics, translating concepts like Hawking radiation and the beginning of time into images a non-specialist can follow. The film keeps returning to a central puzzle in his career: how a mind pushing the limits of cosmology operated inside a body increasingly limited by motor neurone disease. It is less a survey of black hole physics than a portrait of one physicist's specific contributions to it, told largely in his own words.