Could life on Earth have begun somewhere else entirely? That question drives this look at panspermia, the theory that microbial life travels between planets on comets and meteorites, first proposed in the 1960s by Fred Hoyle and Chandra Wickramasinghe and dismissed for decades before NASA started taking it seriously. The film follows a Texas team building DEPTHX, a robotic submarine designed to hunt for life in extreme underwater environments as a rehearsal for exploring Jupiter's moon Europa. It then travels to Kerala in southern India, where a red rain fell for two months in 2001, coating the region in a crimson residue. Scientist Godfrey Louis explains his analysis of that rain: cells with no detectable DNA that can reportedly reproduce at temperatures around 300°C, a property no known Earth organism shares, and his argument that they arrived from space. Interviews with astrobiologists and footage from both the submarine project and the Indian countryside carry the case, building toward the possibility that every living thing here traces back to a cosmic import.