When fourteen-year-old Clem Crabtree loses two of his white king pigeons, he see them in the wild when he makes grocery deliveries to one of the two local houses of prostitution, which are near the store in Langston, Mississippi, a visible town of heavy racial discrimination after the hostilities in Korea are over. Permission to attempt to capture the birds is given by the brothel owner, alone and at night, who was a friend of the boy's deceased father.
On a trip to the house, Clem sees part of a sexual encounter and is terrified, so he goes home. Later, after his fears subside, he makes other trips to the house (Nanny's), and on one of the later trips, he sees the owner and a patron of the house in an argument. The patron vows to kill the dago owner. The owner, Emanuel Flowers, wants Clem to do a favor. They agree to meet in secret at the local swimming hole, the boxcar hole.
Clem is careful, so he hides his bike and himself to wait for the arrival of his friend. Other cars, even a police car, appear behind the friend, and as Flowers exits his vehicle, he is shot with a rifle and is then killed with a handgun that Clem sees and is horrified. He sees them take a child out of the vehicle, blindfold the boy, give him a shot in the arm, and toss both bodies into the boxcar hole. They leave, and the terrified boy does not know what to do. He swims out and rescues the child. On investigation, he sees that the child is the grandson of Salmo Mancha, a New Orleans Mafia boss, and Mancha is the older brother of the just-killed Flowers.
Clem manages to get himself and the child on a train toward New Orleans under the guise of going to the Scout jamboree in Houston, Texas. Clem and the child are met in Picayune, Mississippi, by Salmo Mancha and an entourage. Clem gives the details to Mancha and his men.
Before the shooting incident, Clem's mother is married to a local well-to-do attorney, and the two leave Langston for a six-week honeymoon to Bermuda and then on to Europe. Since his stepfather's employees do not know much about him, he can make do until Mancha takes him back to Langston for his September classes. Successfully placed in his new home, he is ready to make a go of school but comes down with an illness.
Awakening from a bad dream and deathly ill, he is comforted by a man that he thinks is his new stepfather. But it is his new grandfather: Emerson Hebert. The man and ill child bond over the several days it takes the parents to get home from their honeymoon, and they make plans to assist the FBI and local policemen in solving the killing in cold blood. As the new grandfather, a well-to-do attorney, learns from Clem what he has seen and has made him fearful for his own life, his grandfather and the Mafia boss go after the killers. Hebert is seeking legal justice from the courts; Mancha is seeking street revenge, Salmo's way, to hell with the courts and their justice.
