The search for life beyond Earth starts with life on Earth itself. This film opens in the planet's most extreme environments, deep-sea vents, acidic pools, and Antarctic ice, where microbes called extremophiles survive conditions once thought lethal to biology. Scientists explain how these organisms reshape the odds for life on Mars, Europa, and Enceladus, and the film traces the chemistry that may have sparked the first living cells billions of years ago. Interviews with astrobiologists and planetary scientists walk through competing theories of life's origin, including the possibility that its building blocks arrived from space via comets and asteroids. Animation and telescope imagery stand in for the places cameras cannot reach, from hydrothermal vents to the frozen crust of distant moons. Rather than settling on a single answer, the film builds a case for why life might be far more resilient, and far more widespread, than Earth's familiar biology suggests. It is the opening chapter of a series asking how humanity fits into that picture.