In the future, human society is color coded, with Reds being the lowest on the rung. Darrow is a Red, and works with the other Reds to make the surface of Mars livable. However, one day by chance Darrow discovers that Mars has already been terraformed and colonized, and that he and the Reds are merely slaves. Determined to get out of his class, Darrow infiltrates the Institute and competes with the Gold class to become part of the next generation of human overlords.