Billy (Mark Duplass) and Ray (Sterling K. Brown) are lifelong best friends, brothers from another mother – and the last two men on earth. Their survival is largely due to Ray, a brilliant scientist who designed a domed structure with all the systems necessary to sustain life on a planet that could no longer support it. Their custom biosphere is outfitted with basic necessities and creature comforts that make it possible to retain a sense of what life used to be like. A hydroponic garden provides fresh vegetables and a carefully managed fishpond supplies essential protein. Recently, however, fish have begun dying at an alarming rate. With a mere three fish remaining, Billy and Ray face an ominous future. But life may yet find a way.