Enceladus, a small moon of Saturn coated in ice so reflective it ranks among the brightest objects in the solar system, sits at the center of a wider survey of the outer planets' icy satellites. The film traces the discoveries back to 1979, when the twin Voyager probes used a rare planetary alignment to fly past Jupiter, Saturn, Uranus, and Neptune, sending back images of Io's sulfur volcanoes, Triton's nitrogen geysers, and Miranda's jumbled, refolded crust. Footage and animation explain how Europa's cracked, ridged surface points to a liquid ocean warmed by tidal friction from Jupiter's gravity, a finding later reinforced by the Galileo mission. The narrative then turns to Cassini, which reached Saturn in 2004 and in 2005 spotted plumes of water vapor jetting from Enceladus's south pole, where temperatures run up to 65 degrees warmer than the -315-degree equator. The film closes on the question driving the mission: whether Enceladus and Titan hide oceans beneath their ice, and whether those oceans could support life.