Darrow is a Red, a member of the lowest caste in the color-coded society of the future. Like his fellow Reds, he works all day, believing that he and his people are making the surface of Mars livable for future generations. Yet he toils willingly, trusting that his blood and sweat will one day result in a better world for his children.

But Darrow and his kind have been betrayed. Soon he discovers that humanity reached the surface generations ago. Vast cities and lush wilds spread across the planet. Darrow—and Reds like him—are nothing more than slaves to a decadent ruling class.