It is the end of the day at a defense plant. William Sturka is having a smoke, and is joined by Mr. Carling, a government agent. He tells Sturka that nuclear war is coming within 48 hours and seems to be pleased by the fact. Sturka doesn't share Carling's feelings about it; Carling warns him about what he says and thinks. Sturka says goodbye and heads home.
At home, Sturka is met by his daughter Jody and wife Eve. Jody senses her father is troubled and asks about his job, working around bombs. Sturka tries to downplay his role making them. Jody then brings up that there's "something in the air" and its making everyone afraid. Sturka lashes out against the fear but quickly reins it in. He asks his wife to invite Jerry Ryden, a test pilot, and his wife Ann, over for dinner, and insists that Jody stay home that night.
Sturka and his wife go upstairs and he tells Ann of the impending holocaust. He then tells her that he and Jerry have a plan to get away and that no one else must know about it. Downstairs, Jody calls out to her father that Jerry is here to see him. Sturka and Jerry start a conversation about Jerry's watch, and head to Sturka's workroom to continue their talk. Ryden tells Sturka that they have a new guard on the field where their ship is. Sturka says the plan must go on, and leave the workroom, unaware that Carling has been outside, listening in on them.
After dinner, the Sturkas and Rydens are playing cards. During a break in the game, Ryden shows Sturka a piece of paper of where they are headed, nearly eleven million miles away, and from radio signals, is just like their world. Their game is interrupted by a visit from Carling. He brings up the subject of the new ship that Ryden had been testing and the possibility that it can go into outer space. Carling picks up the piece of paper with the destination on it but doesn't see it because its facing away from him, though he hints about the next 48 hours. Sturka sees Carling to the door, where Carling wonders aloud about the possibility of life on another planet.
After Carling leaves, Sturka announces to their families it's time to leave. Jody wants to know where they are going and Sturka says they are headed to outer space.
The Sturkas and Rydens drive to the government field where the ship is. Using their car lights, they signal to the guard to let them in. But it's not the guard: it's Carling, gun in hand. He orders the women to come out of the car. Jody opens the door hard on Carling, knocking the gun out of his hand; Sturka and Ryden overpower Carling and knock him unconscious.
They drive onto the government field, ignoring warnings from guards. The families get out of the car, and board the ship, taking off.
The ship flies through space. Sturka and Ryden look out at the stars, looking at their destination in the distance. It's a bright shiny planet, the third planet from the sun. It is called Earth.