Plot
In the summer of 1910, a group of circus monkeys named Henri, Jacques, Antoinette and Dominique escape from a French circus due to a train wreck and end up in the Oklahoma river bottoms, where the main character, Jay Berry Lee lives with his family.
Weeks later, 14-year-old Jay Berry Lee is fighting a bully named Toby on the last day of school when Jay steals Toby’s prized pocketknife. Their teacher Miss Freeman stops the fight, returning the pocketknife to Toby. Jay later visits a man, Mr. Patterson, at his horse ranch and is desperate to buy Annie - his favorite horse. Mr. Patterson promises Annie to Jay only if he pays no less than $75. When Jay returns home, he is punished from dinner for the fight. When Daisy, his crippled sister, sneaks a biscuit to him, she sees Jay's drawings of the horse. She then explains her own resentment, relating to her brother, as their parents forbid her physical activity due to her condition.
The next morning, Jay arrives at his Grandpa Sam Ferrans' general store looking for a job so he can earn enough money to buy himself a horse. On the way there, his dog Rowdy goes to explore the forbidden river bottoms. Jay hears monkeys screeching in the distance and after visiting the store, he then discovers the monkeys camping on the drunk Bayliss Hatcher's property. Jay tells Daisy his discovery, but she doesn't believe him. Jay returns to his grandfather's store and finds a wanted poster of the monkeys, paired with a bounty of $85. Toby and two other bullies also find the poster and set out to trap them. Jay makes a trail of apples leading the monkeys to the family farm, to trap them under a heavy box. The trap fails, so Jay borrows a monkey doll from Daisy for bait and places a padded bear trap. The monkeys instead go to the house once more and wreak havoc while nobody is home. Daisy sets out to follow Jay to the bottoms, when Bayliss Hatcher steps in the bear trap and accidentally shoots his gun into the sky. Scared by the gunshot, Daisy falls down a steep hill. Jay hears Daisy calling for help and comes to her rescue. Their parents, seeing the monkey's mess, get into an argument with Jay and ground him from working at Sam's store for the next two weeks.
The next day, Jay runs away. He heads back to the river bottoms to get revenge on the monkeys. He finds a box containing a photo of a young Bayliss Hatcher and his family and runs to Bayliss' cabin to make a deal with him about the monkeys and to return the box, while begging him not to shoot them. Bayliss finds out that Jay had set the bear trap and gets angry. Sam finds Jay and decides to take him to Ridgewell so he can research the monkeys. Jay's parents are reluctant as Jay has been disobedient, but Sam tells Mrs. Lee about when he forbade her to go to the fair to enter her pet pig in a contest. His parents agree. Sam takes Jay to the library where Jay researches chimpanzees, learns many ways to train monkeys, and meets a woman named Rose who teaches him how to speak some French words. Sam later shows Jay the house Bayliss used to live in and tells Jay that Bayliss' family left him due to his drinking. Later, when returning with Rowdy to the bottoms, Jay saves Jacques the monkey from Toby's dangerous non-padded bear trap that would have killed the animal. Toby, in a fight with Jay, hits Rowdy with the bear trap, injuring the dog. Bayliss Hatcher suddenly appears, scares the bullies away, and heals Jay and Rowdy.
After Jay returns home, he sets up a place in the barn for the monkeys and begins to build a cage for them. A storm arrives, bringing along a tornado that destroys the farm's surroundings. Afterward, Jay discovers Bayliss' cabin was destroyed, and that Bayliss has died in the wreckage of his collapsed house. Heartbroken, Jay goes with his father to get supplies for repairs. Before they go, Daisy shows her family a garden of mushrooms that have appeared. Jay later discovers that Jacques the monkey is dying and takes him home for care. The other monkeys also arrive at the farm, following Jay. The owner Jobert, soon arrives at the farm and gives Jay $85 for finding and returning his chimpanzees.
In the morning, Jay borrows Annie from the ranch and gives Daisy a horseback ride. Upon returning, Jay notices his father making a new horse stall for Annie, but Jay tells him not to, explaining that the $85 will instead pay for Daisy's life-saving operation. Daisy overhears and gives Jay a hug of deep gratitude. Jay then walks Annie back to the ranch.
