Somewhen in the future, Humans have colonized Mars, and, like the Earth before it, they plunder the Red Planet's natural resources on the backs of slaves.Young Darrow, a Red helldiver, is content with his lot, living in the cramped Common with his beloved Eo deep beneath the surface as the Reds mine for precious helium 3, so that one day the surface will be a new Eden for their children's children's children. When Darrow learns the truth, that the glorious surface cities the Golds promised the Reds' sacrifices would someday make possible already exist, peopled by all colors except the lowest Reds, he vows to raise Red as high as Gold.