After 35 years of living on the Moon, cranky old oxygen farmer Millennium Harrison has stumbled onto a hidden facility in the shadows of the Slayton Ridge Exclusion Zone with a radiation leak and a deadly secret. Mil's discovery leads to the death of a young astronaut, sabotage, murder, and cover-ups that may go all the way to the Chief Administrator of the space agency. Unfortunately, she happens to be Mil's estranged daughter, busy trying to secure her own legacy-the first international mission to Mars.