Augustine, a brilliant, aging astronomer, is consumed by the stars. For years he has lived in remote outposts, studying the sky for evidence of how the universe began. At his latest posting, in a research center in the Arctic, news of a catastrophic event arrives. The scientists are forced to evacuate, but Augustine stubbornly refuses to abandon his work. Shortly after the others have gone, Augustine discovers a mysterious child, Iris, and realizes that the airwaves have gone silent. They are alone. At the same time, Mission Specialist Sullivan is aboard the Aether on its return flight from Jupiter. The astronauts are the first human beings to delve this deep into space, and Sully has made peace with the sacrifices required of her: a daughter left behind, a marriage ended. So far the journey has been a success. But when Mission Control falls inexplicably silent, Sully and her crewmates are forced to wonder if they will ever get home. As Augustine and Sully each face an uncertain future against forbidding yet beautiful landscapes, their stories gradually intertwine in a profound and unexpected conclusion.