Boy's Life is a novel by bestselling author Robert R. McCammon. In this novel, Cory Mackenson shares with the reader his experiences in the twelfth year of his life. The year begins when his father attempts to rescue a driver as his car plunges into Saxon's Lake, only to discover the man has been beaten to death. Cory spends the rest of the year, despite multiple distractions, attempting to find out who killed this stranger before his father's dreams drive him into the depths of the lake too. Boy's Life is a story of coming of age in the south, an all too real reality mixed with the magic and fantasy of childhood.

Cory gets up early to help his father work his milk route. As they discuss Cory's plans for the future, they drive through their little town of Zephyr, Alabama. When Cory's father begins to drive past Saxon's Lake, they are both shocked when they see a car race across the road in front of them and plunge into the lake. Cory's father dives into the water to rescue the driver only to discover the man has been horribly beaten and strangled. Someone has stripped the dead man naked and handcuffed him to the steering wheel to prevent his body from ever rising to the surface again. Cory and his father rush to the nearest house, which happens to be a brothel managed by a woman named Grace, and call the police. Unfortunately, there is little the police can do without a victim, a name, or a motive.

People talk about the murder for weeks, disturbed that such a thing could happen in their small town. However, with no progress on the legal end of things, people soon forget. Easter comes. Cory and his family attend church with both sets of grandparents. The day is extremely hot and the church is packed. Within moments of the pastor beginning his sermon a nest of wasps become agitated in the attic and wasps begin invading the church. Within moments the entire congregation is rushing for the doors, hoping to escape their horrible stings.

Not long after Easter, Cory's bike dies. Cory goes to retrieve it with his father, but they learn that the junk man has picked it up. At the junk man's house, Cory learns that his bike has already been crushed. However, Cory and his father get to see a tooth that possibly came from the mythic creature that lives in the Tecumseh, Old Moses. Not long after this, rains bring a swelling of water in the river, leading to a flood. The whole town of Zephyr rushes to Bruton to build a temporary dam to hold the waters back. While there, Cory goes to the home of a local woman whose father is having a heart attack. Cory is left alone with a little boy while his mother and the boy's mother move the old man to dry ground. A creature floats into the house and attempts to attack Cory and the boy. Cory manages to fend him off with a broom, shoving it so far in the back of its throat the creature backs off. As a result of his heroics, Cory is invited to visit the Lady, the honorary leader of Bruton, and promised a new bike.

School finally gets out. Cory and his friends rush off to make plans for their summer. When Cory gets home, he discovers that he has received the promised bike from the Lady. The bike is new and has everything a boy could want, including what Cory believes is a golden eye in the headlamp. A few days later, Cory and his friends meet at the baseball field. A new boy in town, Nemo Curliss, watches them toss the ball for a time. Cory invites him to play too. Nemo turns out to have a powerful pitching arm, strong enough to bruise Davy Ray's hand when he catches Nemo's pitch. As they play ball, the Branlins come upon them. The Branlins begin to tease the younger boys as they often do. When the Branlins begin picking on Nemo, Cory and his friends defend him. The Branlins begin to beat the boys, leaving Cory and Davy Ray hurt, but Johnny Wilson with a concussion.

One afternoon at the public pool, Cory hears a new song by a new group called the Beach Boys. Cory is excited by this new song. However, a local preacher is not as impressed. In fact, he has a special church service to lecture the community on the evils of this new music. Cory and his family attend out of curiosity. During the sermon, the preacher pulls out a monkey he calls Lucifer. Lucifer becomes frightened by the crowd and attacks the preacher. Lucifer then attacks the congregation before escaping through the open door.

A short time later, Cory spends a week with his paternal grandparents, Jaybird and Sarah. Cory dislikes his Granddaddy Jaybird because he always wakes him before dawn and makes Cory do some of the harder chores around the farm. On Cory's last day at the farm, Granddaddy Jaybird takes him to the store to buy ice cream salt. However, instead of going home, Granddaddy Jaybird takes Cory to a house where an illegal poker game is going on. Cory waits for several hours outside and finally gives up, deciding to walk home. Finally Cory is picked up by the local doctor who drives him back to the farm.

As a deal with his father to go to Jaybird's, Cory is allowed to go camping alone with two of his friends. The boys walk deep into the woods and settle down for the night. Cory tells a scary story. In the middle of the story, they see a car drive past their campsite. The boys follow the road and find two men waiting in their car. The boys watch as another car drives up and the men transact some kind of business with these new arrivals. Ben becomes covered with spiders and screams out, attracting the attention of the men. The men chase the boys through the woods. Cory is separated from his friends. The following day Cory comes across a girl skinny dipping in a pond. The girl takes him home, cleans his wounds, and arranges for him to get a ride to a phone.

Cory wins third prize in a writing contest. The mayor calls and asks Cory to meet him at his office. Once there, Cory sees a hat with a green feather in it and jumps to the conclusion that the mayor is the killer. Cory becomes frightened and runs off. However, the feathe on the mayor's hat does not match the one Cory found at Saxon's Lake. Cory wins a plaque and has to read his story at a ceremony. A few days later, Cory is invited to have dinner with Vernon Thaxter, the son of the local bank owner.

Back at school, Johnny brings his collection of arrowheads. After school, the Branlins attempt to steal the arrowheads. Johnny fights Gotha, using the boxing techniques he learned from a book during his long recuperation from his concussion. At the same time, Cory leads Gorda off on his bike and causes him to fall into a ditch filled with poison oak. Neither Branlin ever teases or bullies Cory and his friends again.

One afternoon Cory comes home from school to learn that Rebel, his dog, has been hit by a car. Cory rushes to the vet to see his dog, only to learn he is dying. Cory prays death away. Rebel recovers, but he is never quite right. One night Cory hears someone talking to his dog. Cory realizes it is a young boy who once lived down the street, but died in a fire. Cory realizes it is time to give up Rebel. Cory arranges to have the vet put Rebel down. A short time later, Cory is riding his bike in town and is kidnapped by Donny Blaylock, one of the men he saw transacting business during his camping trip. Donny plans to hurt Cory, but instead he is distracted by the memory of a man he killed on that road. There is a car accident and Cory is freed. However, Donny is arrested for murder.

The sheriff, it turns out, has been taking bribe payments from the Blaylocks. As a result, he is leaving town. However, before he leaves, the sheriff wants Donny to be taken by the state police. The sheriff asks Tom Mackenson for help. At first Tom refuses, but later agrees. There is a shootout that ends when Biggun Blaylock's ammunition turns into green garden snakes.

A short time later, the Brandywine Carnival comes to town. At the carnival, Cory and his friends see everything from the haunted house to a baby with one eye. Cory drags them off to see a creature that appears to be a triceratops. Davy Ray is deeply affected by seeing this animal, so when Cory learns the next day that someone helped the animal escape, he suspects it was Davy Ray.

That fall, when hunting season begins, Cory finds himself thinking about parrots and green feathers. However, before Cory can investigate his suspicions, he learns that Davy Ray has been shot in a hunting accident. Cory and his family rush to the hospital. Cory tells Davy Ray a story about a solitary traveler. The following morning, Cory learns that Davy Ray has died. Cory does not know how to deal with the death of his friend, especially when his mother and pastor tell him he must have faith that Davy Ray is somewhere better.

When Cory learns that the vet and his wife had a green parrot in their home the night the stranger from Saxon's Lake was killed and that they both are allergic to milk and therefore would not have thought of seeing a milk man out before dawn, he begins to suspect they killed the man. At the same time, Cory's father finally goes to see the Lady after he goes to her for help dismantling a bomb. At this meeting, Cory's father is told the number thirty-three is important. The only thing Tom can find with that number is a bus that comes to town every other day. Tom takes a job at the gas station where the bus drops off passengers and waits. On the day someone finally gets off the bus, Cory goes to the vet's house to spy on him, to try to prove he killed that stranger.

Tom learns that the dead stranger was a Neo-Nazi who helped hide a couple of German officers in Zephyr years before. The man came to town to blackmail these Germans to start a new life. Tom cannot imagine which of his neighbors might be German officers who could be so cruel as to pick and choose which Jewish prisoners should die. However, when Tom learns the German officer was a veterinarian, he begins to suspect Dr. Lezander, the local vet. Tom and his new companions go to the vet's house where they discover Cory is being held against his will. Dr. Lezander takes off with Cory. Tom follows. When they reach the road that runs beside Saxon's Lake, the triceratops comes out of the woods and attacks Dr. Lezander's car, pushing it into the water. Tom saves Cory, but can do nothing for Dr. Lezander.

Cory returns to Zephyr many years later with his own family. The town was abandoned after the paper mill closed down in the 1970s. Cory drives to all his familiar haunts, finally stopping at his family's home. Before leaving, Cory decides to drive to the Thaxter mansion. There, Cory discovers that the mansion was given to an orphanage for boys and several people he knew in childhood still live there, working with the little boys.