When evidence of microscopic life on Europa—Jupiter’s sixth moon—is discovered, a crew of astronauts and scientists embark on a mission to discover its source. Led by oceanographer and biologist, Kathy Connelly, the crew is charged with the task of melting through miles of ice to the hidden ocean beneath, where the search for alien microorganisms begins. But a startling discovery awaits them on the surface of Europa—life.

Vast fields of red, plant-like organisms fill the cracks crisscrossing the moon’s surface, surviving on nutrients welling up from the waters below. Encouraged by the discovery of life on the surface, Connelly and her crew activate the Thermal Exploratory System and melt through the ice toward a world that does not want to be found, toward an intelligence that will do anything to make sure they never leave.