Hattie Johnson’s children are buzzing with anticipation over the news: for the first time in twenty years, a white man is coming to Mars. The rocket is due to land later that day, and although her young boys are excited, Hattie has a feeling that the white man’s visit will stir up trouble. Her kids pester her to tell them what white people are like and why they don’t live on Mars. Hattie explains that white people live on Earth, and that twenty years ago, the Martians did too. Eventually, the Martians “just up and walked away and came to Mars,” but the white people stayed on Earth and entered into a terrible atomic war with one another. It wasn’t until recently that the Earth people scrapped together enough metal to build a single rocket to reach Mars.
Telling her children to stay at the house, Hattie runs down the road and sees her neighbors, the Browns, piled into their family car. Mr. Brown says they’re on the way to see the white man. Hattie tentatively asks the Browns if they’re going to lynch the visitor, but the Browns laugh and assure her that they’re going to shake his hand.
Willie, Hattie’s husband, pulls up in his car and gruffly asks the Browns if they’re going to see the white man “like a bunch of fools.” He adds that he is on his way home to get his guns, and that they should consider doing the same. Willie then forces Hattie to get into the car with him, and the two speed home. Willie mutters about why the Earth people couldn’t just stay on their own planet and “blow themselves up.” Appalled, Hattie tells her husband that he doesn’t sound very Christian. Willie asks Hattie if she remembers all of the terrible things the white people did to the Martians, and how Dr. Phillips and Mr. Burton hanged his father on Knockwood Hill and shot his mother. Now, with the arrival of the white man, “the shoe’s on the other foot.” Willie adds that, on Mars, white people will have discriminatory laws leveled against them, be forced to ride in the back of streetcars and sit in the back of theaters, and even get lynched.
The car pulls up in front of the Johnson household, and Willie dashes inside in search of guns and rope. Hattie reluctantly follows her husband into the house and watches him bustle around the attic, collecting his guns and muttering madly to himself. Hattie notices that his face looks twisted with bitterness and hatred. Barreling outside, Willie rounds up the children and tells them that he’s locking them up—he doesn’t want them to see or even talk about the white man.
On the way to watch the white man’s arrival at the landing port, Hattie notices that other cars are filled with guns. She accuses her husband of provoking people in the community, and Willie proudly reveals that he stopped at every house earlier that day and told everyone to bring guns and ropes. Hattie asks her husband to think about what he’s doing, but he snaps that all he’s done for the past twenty years is think about white people and the cruelty and racism the Martians endured on Earth.
A dense crowd gathers at the landing port, and Willie passes out guns. When a trolley car pulls up, Willie climbs up into it, lugging a gallon of paint. He begins painting the seats, and the conductor quickly objects. However, when Willie steps back to reveal his handiwork, the conductor is pleased. The seat reads, “For Whites: Rear Section.” Willie asks for volunteers in the growing crowd to paint every streetcar in the city. Several people race off to begin their task. Willie also asks the crowd to rope off the back two rows in the movie theaters, and several volunteers are chosen. On a roll, Willie shouts that new laws need to be passed banning intermarriages. The town’s mayor tries to get Willie off of his soapbox, saying Willie has formed a mob and is behaving no better than the white men he is shouting about. Unfazed, Willie responds, “This is the other shoe, Mayor, and the other foot.” Willie yells to the crowd that they will elect a new mayor.
Clutching a noose in his hands, Willie asks the crowd if they’re ready. Half of the crowd calls back enthusiastically, while the other half looks “like figures in a nightmare.” The white man’s rocket soars across the sky and begins its descent. When it lands, the crowd goes silent. The rocket’s door slides open, and an old, tired-looking man steps out.
The old man doesn’t introduce himself, saying it doesn’t matter who he is. He tells the Martians that twenty years ago, when they left Earth, World War III broke out. Since then, most of the Earth has been destroyed by atomic bombs. Historic cities like Paris and London have been reduced to smithereens. Even small cities, like Greenwater, Alabama, have been annihilated. Hearing the name Greenwater, Willie’s mouth drops open. The old man continues, explaining that cotton fields, cotton mills, and factories have all been destroyed. Everything is radioactive, including the livestock, food, and roads.
The old man continues that there are only five hundred thousand people left on the entire planet. Calling the Earth people fools, he asks the Martians for permission to use their rockets, which have been sitting unused for twenty years, so that he can bring the Earth people to Mars. He reaffirms that Earth people have been stupid and evil, and adds that they will work for the Martians and endure whatever treatment they see fit.
When the old man finishes his speech, the crowd is silent. Many people watch Willie carefully to see how he will react. Watching her husband, Hattie thinks about how she wants to chip away at everyone’s hate so that eventually, all hatred and racism will crumble. She realizes that if husband lets go of his bitterness, then maybe everyone else will too. Boldly stepping forward, she calls for the old man’s attention, asking if he knows “Knockwood Hill in Greenwater, Alabama?” When the old man produces a map, Hattie asks about the big oak tree on the top of the hill. The old man says that the hill and the tree are both gone. Hattie asks if a certain Dr. Phillips and Mr. Burton are still alive, and the old man replies that they both died in the war and both of their houses burned down. He adds that there are no surviving houses or people in Greenwater.
Willie thinks about how there are no more “lynching trees,” pubs, or plantation homes. There is nothing “left to hate,” except for an “alien people” who will be forced to sit in the back of streetcars and theaters. Quickly, Willie tells the old man that Earth people won’t have to work for the Martians. Upon seeing Willie drop his noose, the other Martians swiftly unload their guns and race through town, tearing down all of the freshly painted signs and newly installed ropes.
On the way home, Hattie muses that everyone will finally have a fresh start. Willie tells her that in the past twenty years, the Earth people have endured the same feelings of pain, loneliness, and homelessness that the Martians experienced on Earth, meaning that now everyone is “on the same level.” When Hattie and Willie get home, Hattie lets the children out of the house, and they excitedly ask their father if he saw the white man. Rubbing his temples with his fingers, Willie answers that he did: “Seems like for the first time today I really seen the white man—I really seen him clear.”