A nineteen-year-old boy hitchhikes on the side of the road in Kansas. He is returning back to summer school from Oklahoma. A blue Plymouth coupe passes by him with a man and a woman happy laughing but they do not notice him. Half an hour later, a Ford pickup truck stops and the owner lets the boy in. The man looks about forty and asks the boy if he saw a blue Plymouth pass by recently. The boy answers yes, and the man reveals that the car had his wife and the man she has an affair with. The man plans to kill them both and has a gun in the truck to prove it. After the man shuts down the boy's suggestions that he just call the police about his wife, the boy keeps quiet and gets out the truck when they reach Lawrence, Kansas. He constantly looks at the news to see if a killing ever shows up but nothing seems to surface. The summer comes to an end and soon enough the boy has grown. He has a family of his own with two sons. When he and his family move to Michigan, the man tells his son about his encounter with the mysterious armed man in the pickup truck. The boy grows old and gets so sick that he requires morphine shots and finds himself unaware of passing time. The boy's memory of the gunned man replays several times in his mind. In the first replay, the man with the boy in the truck finds the blue Plymouth and shoots his wife, her lover, and then aims the gun into his own mouth.  The second time, the boy talks the man out of his plans to shoot his wife and her lover and they go to the police station. The boy tells the sergeant the truth and the man gets his gun taken away but he feels less guilty.  The third time, the boy stays silent during the whole car ride with the man until he gets out and reports the man to the police. Later, he hears a gunshot and finds the man shot dead and lying half out of his pickup truck while police are grinning and clapping each other on the back for hitting their target.  The fourth time, the boy tries to convince the man that his actions are immoral. When they arrive at the train station, he sees the wife and her lover and stands in between the gunned husband and the wife. To his surprise, the man shoots him in the shoulder and the in the back.  In present time, the boy, now an old man, passes away before his family. His sons sadly watch their father’s body wrapped up in a body bag and this image replays in their minds.