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. But he discovers that humanity reached the surface generations ago. Vast cities and sprawling parks spread across the planet. Darrow—and Reds like him—are nothing more than slaves to a decadent ruling class. Inspired by a longing for justice, and driven by the memory of lost love, Darrow sacrifices everything to infiltrate the legendary Institute, a proving ground for the dominant Gold caste, where the next generation of humanity's overlords struggle for power.