In the 1950's, young Carrie Staley witnesses a murder while riding on a bus in Brooklyn, New York. Her father sends her to spend the summer with his relatives in Missouri. Landy, Bea, and Lucy Bretthorst welcome her warmly. She and Lucy are the same age and quickly become friends.Landys sister, Grace Bretthorst Jones, is coming home after spending seventeen years in the state mental hospital. She was hit by a car and seriously injured while crossing the road to pick flowers. While her physical injuries healed, she was left brain-damaged and unable to function normally. Eventually her husband Dan divorced her. Landy felt she had improved enough to come home, so he petitioned the court for her release. He, his daughter Lucy, and Carrie go to collect her. It is a long drive and they spend the night camping along the road.The hospital director is very much against Grace's release. She believes that Grace is not normal and won"t be able to cope with the outside world. Landy's only contact with her in years has been by telephone. He brushes aside the director's doubts and talks about the welcome home party he and Bea have planned to re-introduce Grace to the townspeople. If they see her, they will realize she is fine. Just as they leave, the director recommends that Grace be kept away from the children.Lucy enthusiastically greets her aunt but Grace's response is lukewarm. At the party, she is obviously ill-at-ease. Her eagerness to see Dan again fades when she learns not only is he married again, but his wife Ella Dean is pregnant. Dan takes Grace aside and explains that the doctors told him she would never get better. He thought he had no choice but to divorce her. Grace embraces him as if he were still her husband. It is as if she hasn't understood anything he said. Heavy rain falls nearly every day, causing great concern about flooding. Landy owns a bakery downtown and gives away free bread to the black families who had to evacuate their homes. This doesn''t set well with his pastor, Rev. Potter, who wonders aloud why he has never received anything free from the bakery. Landy is also caring for an injured fox who was found among the rubbish behind the shop.Carrie and Lucy sneak out at night to attend revival services at the black church. Lucy intends to convert even though she is already a Baptist. She loves the style of worship and how everyone is so friendly.Grace's family tries hard to make her feel at home. Landy offers her a job at the bakery and Bea invites her to go shopping. After she sews an exquisite dress for Lucy's doll, the girls ask her to make one for Carrie. A boy from the nearby military academy has asked her to a dance. Grace tells them the story of her romance with Dan and how she never loved anyone but him. She was just seventeen when they married and the accident happened on their honeymoon. The heavy rains continue. Landy assists with placing sandbags in case the river overflows. Ella Dean, hearing that Grace likes to sew, brings her some quilt pieces. Grace shuts the door in her face and drops the pieces on the floor, showing her contempt. People are now starting to feel uneasy about Grace. But Landy won't hear of sending her back to the hospital.Before dawn one morning, Grace and Lucy sneak out to go fishing. They find a rowboat and Lucy insists on borrowing it. But a storm blows up and Lucy cannot handle the oars. She and Grace plunge into the water to swim for shore. But only Grace makes it. Landy arrives and retrieves his daughter's body. At Lucy's funeral, several girls gather around her coffin to add tokens of friendship. Carrie puts in her kaleidoscope, which was a favorite of Lucy's. Bea and Landy are inconsolable. Grace sits apart from them and no one speaks to her. At home, she exhibits bizarre behavior by eating a peach cobbler with her fingers and smearing it on her face. She asks Landy if she will be sent back to the hospital. He says it wouldn't change anything. But Bea is furious and she wants Grace out of her house.Carrie wants to stay on but Bea says it is best if she goes home. She promises to make arrangements as soon as the weather clears. But conditions only worsen. Main Street is in danger of being washed away and Landy is called to help with the sandbags. That same night, Bea invites several of Lucy's friends over for a slumber party with Carrie. But while the girls are sleeping, Grace wanders the house with a pair of scissors. She tries to cut Carrie's hair and the girls awake screaming. Bea sends Carrie for Landy, who locks Grace in a room by nailing the door shut. Their guests are sent home. Landy asks Carrie to sleep with Bea while he stands guard over Grace. But he dozes off and she somehow manages to escape, after trashing the room.Several men, including Dan and Landy, start a search. Landy begs that Grace not be hurt. Bea spots Grace on the roof of Dan's house, where Ella Dean lies sleeping. She angrily orders her to come down. They go into the Jones's living room, where Grace stabs Bea in the chest. A neighbor woman runs in and assures Bea that she is going to be all right. After Bea is taken to the hospital, Ella Dean wakes up and realizes she is in labor. But there is no one about. She makes her way to the front porch, calling for help, and Grace responds. She leads Ella Dean into the house and assists her in giving birth to a baby girl. A grateful Ella refers to the baby as little Grace.The next day dawns clear. Landy is shown hammering together a cage on the back of his pickup truck. When it is ready, several men unlock the garage door and lead Grace out. She doesn't seem to know what is happening. But when Landy tries to force her into the cage, she begins screaming and begging him not to send her back. Carrie comes out with a suitcase. Landy tells her he has arranged for a woman he knows to take care of her until it is time to leave for the airport. Her father will meet her at the other end. She begs to go with him all the way to the mental hospital. But taking Grace back is something Landy has to do alone.As they drive away, the street is lined with people. Rev. Potter tells Landy that he is a good man. Grace is silent, hunched over so she will not see the stares. Landy drops Carrie off at the woman's house. As a parting gift, he returns the kaleidoscope she had tucked into Lucy's coffin. He tells her Lucy would want her to keep it.Here a much-older Carrie is heard telling the rest of the story. Landy is shown releasing the now-healed fox back into the wild. Bea did not survive the loss of her daughter or her injury. Carrie wrote to Landy several times but he didn't reply. Years later, she heard from one of Lucy's friends that he left town one day and no one ever saw him again. Carrie never heard anything more about Grace. Here the scene switches to Grace standing alone in the moonlight next to Landy's truck, stretching her arms out and smiling. A gunshot is heard. The last scene shows Landy sitting next to a river, his shotgun at his side. Obviously Grace never made it back to the hospital.