Darrow, the narrator, works in the mines on Mars, a life of drudgery and subservience. He's a member of the Reds, an inferior class, though he's happily married to Eo, an incipient rebel who wants to overthrow the existing social order, especially the Golds, who treat the lower-ranking orders cruelly. When Eo leads him to a mildly rebellious act, she's caught and executed, and Darrow decides to exact vengeance on the perpetrators of this outrage.