Fourteen-year-old Claire is a Vessel, a girl chosen to be implanted with a child, who will, about a year after its delivery, be given to a married couple to raise. The process does not go smoothly for Claire, and the medical staff is forced to cut the Product from her body. She is removed from the Birthmother Dormitory and sent to work among the Fish Hatcheries, as it is determined that she will not be able to deliver another child without complications. Before she leaves the area, she is able to discover that her child, number 36, was a boy and did survive birth.
Claire struggles to fit in with others in the Fish Hatchery. Although she enjoys the work and the people, she is haunted by thoughts of her son. Eventually, she tracks him down in the Nurturing Center. She volunteers to help with the babies in her free time so she can be near her son. One of the workers at the facility regularly takes 36 home at night, hoping that the added stimulation will help the child. It also allows the other babies a better night's sleep because 36 cries throughout the night. Claire develops a kind of friendship with the Nurturer who does this, learning his habits so she can "bump" into him as he takes 36 on errands or to his home.
It is on one of those meetings that she learns 36 was not given to a couple to raise, but will be spending more time at the Nurturing Center to see if he can acclimate to society. Claire also learns the Nurturer has a boy named Jonas who will soon be going through the Selection Ceremony. At 12, all children are given their occupations in the Community. After the Ceremony, Claire is told that a boy named Jonas was not given his Assignment. Instead, he was selected. Claire's friends don't understand what he was selected for. They tell her that it has something to do with a Giver and a Receiver.
Claire wonders why she is the only person who seems to have an emotional attachment to her son. He is all she can think about. She never remembers feeling these emotions for anyone else or receiving them from her parents in the past. She realizes it has something to do with the pills everyone else takes daily. Claire used to take the pills, but was ordered to stop while she was a Vessel. Due to an oversight, she was never put back on the medication.
She continues to volunteer at the Nurturing Center. She discovers that 36 will be given the name "Abe" when he is finally assigned. However, as the next ceremony approaches, one of the Nurturers at the Center tells her that Abe will not be placed in a home. The Nurturer refuses to tell Claire what will happen to the boy, but he does tell her that the child's name isn't Abe. That night, sirens sound. Claire's memories are disjointed, but she can recall seeing the Nurturer on a path calling for his son, Jonas. He tells Claire that Jonas has taken the baby and run away. Distraught and confused, Claire runs toward one of the boats in the river. A kind woman takes her aboard when Claire explains that someone has taken her baby. They promise to help her find him. But the ship is torn apart in a storm. Claire manages to survive, but she loses her memory.
Claire finds a home in a new village with Alys, an elderly woman with herbal knowledge. The village is virtually impenetrable, surrounded on three sides by water and on the fourth by a sheer rock cliff. Only one man, Fierce Einar, has climbed it. But Einar has returned to the village, maimed and in pain. Now the young man, just 18, is known as Lame Einar. He no longer fishes with the other men but tends to the sheep in the village.
Claire is a mystery to Alys. The girl seems well educated, but doesn't know her colors or any animals. Alys teaches her about each and how to use herbs to help the sick. When Claire attends a birthing, she flashes on the memory of her own labor. Many in the town are shocked that she, an unmarried woman, had a baby. They don't understand that in Claire's former community, the mothers were impregnated with needles, not by having sex. Once Claire remembers her child, she vows she will find him again.
Lame Einar promises to help her to scale the rock cliff to leave, as she is terrified to go by sea. It takes years of training, in which Einar strengthens both her mind and her body for the arduous task. He also warns her that should she make it to the top of the cliff, she must wait for a mysterious caped man. When that man comes, she must tell him of her one desire. He will offer to trade her something for it. Whatever he wants for the trade, she must agree to it. If not, the man will take revenge. When Einar had refused the man's offer for warmth and comfort after his long climb, the man struck Einar down and cut off half of his right and left feet. That is why the young man returned to his village.
When Claire is finally ready, she leaves the village before dawn and begins to scale the cliff. She encounters many difficulties, including a sea gull protecting her young that pecks and bites Claire as she nears the top of the cliff. At sunset, she reaches the top. She throws down a rock covered in red yarn as a sign to Einar and Alys that she's survived the climb.
At dawn, the strange man appears, just as Einar has said he would. He calls Claire by name. She stands her ground against him, even though he smells foul and is sinister. When she asks that he help find her son, he sneers at her maternal love, but he does make her an offer. He will bring her to her son if she will give him her youth. Claire agrees. Even as she follows the man, her body weakens and her hair grays. The man laughs and tells her that his name is Trademaster and her son's name is Gabe.
Gabe, a young teenager, has spent his life in a village of survivors. Jonas brought him there. Jonas, a man formerly known in the village as Leader, brought him when they were both children. Gabe is embarrassed about his mysterious past. He longs to find his mother, even though Jonas assures him that in their old Community babies really don't have parents. They more or less appeared from the infant-care building and were given to a couple. Now Gabe sets himself to making a boat so that he can sail down the river and hopefully find his mother. He often senses that an old woman is watching him, but he is too shy to ask the woman who she is or what she wants.
Jonas and his wife, Kira, have special powers. Jonas can push his thoughts out and see things in faraway places. Kira can use her embroidery to predict the future. Jonas worries about Gabe, knowing that his search for his mother will be futile. Jonas tells Kira that he senses someone is watching the boy, waiting for him. He believes the person is friendly, so he waits to tell Gabe about his feelings.
As the village prepares for a feast, Gabe recalls the life of his friend Matty. Gabe was 8 when Matty's torn body had been carried in from the forest. The older boy had always been kind to Gabe, teaching him how to fish and fly a kite. Matty sacrificed his life for the villagers, releasing them from the power of the Trademaster. The mysterious man had corrupted the village and, after Matty's death, they vowed to turn from temptation and greed. Instead, they would be kinder and more helpful to each other. Matty had told Gabe to be more attentive at school and learn as much as he could, because one day he would discover he had a gift. Matty had the gift of healing.
Gabe does indeed have a power. He calls it veering. It allows him to place his consciousness into other people so he can hear their thoughts. Once, when he wanted to cheat on a test, he veered into Mentor's thoughts. Instead of seeing the answers, he saw how much his teacher loved his students and his passion to see them succeed. The process exhausted Gabe, but Mentor's thoughts changed him. He vowed he would stop misbehaving and study hard so he wouldn't disappoint Mentor again. Gabe isn't sure how to use this gift or whether he should, so he doesn't tell anyone about it.
Claire watches Gabe in silence. When she first came to the village, she thought about revealing her identity, but changed her mind. He'd been a young boy of 8. She didn't think he would understand. Although her mind is that of a young woman, her body is that of an elderly person.
Several years later, Claire knows she is dying. She worries about Gabe's obsession with his boat. The water has caused her nothing but pain, and she fears it will take her son from her. She decides to tell Jonas her story so he may one day share it with Gabe.
As difficult as her story is to believe, Jonas accepts it as truth, especially after she mentions her deal with Trademaster. They realize they must try and tell Gabe everything. Gabe has finished his boat and set sail down the river. Gabe uses a paddle Jonas made for him to try and steer the boat. It sinks in the current, but his friends pull him to shore. Gabe vows to keep working on it.
Jonas takes Gabe home and tries to explain about Trademaster's power and evil. Although Gabe remembers some of what occurred in the village in the past, he doesn't comprehend the true wickedness in the man's deals. Jonas then tells Gabe about his gift to see beyond. Jonas worries that it is leaving him, but he will try to use it one more time so that he can find Trademaster.
Once the evil is found, Gabe must use the powers he has to destroy it. Gabe worries about Jonas's sanity. Although this Trademaster may be evil, he is no longer a threat to the village, so why should he be killed?
The following day, Gabe finds Jonas in Claire's hut. The old woman is dying. She begs Jonas to tell Gabe her story. Jonas does, but Gabe doesn't believe it. Jonas takes him to speak with Mentor. He convinces the teacher to tell of his dealings with Trademaster.
Mentor longed to remarry after his wife died, but he was older and had an odd red birthmark on his face. Trademaster asked for Mentor's honor in exchange for youth and beauty. Mentor lost the birthmark, stood straighter and grew hair to cover his bald spot. But the woman he desired spurned him because he'd become selfish and mean. He had traded his honor for nothing. When Matty sacrificed himself for the village, all of the Trademaster's bargains were reversed.
Gabe realizes that the story Jonas told him about Claire is true. He must destroy the Trademaster in order to save his mother. Gabe confronts Trademaster on the far side of the river. The cloaked man scoffs at the boy, but Gabe stands his ground. Trademaster holds a large knife to Gabe's throat. The boy knows he has no hope of defeating this evil with weapons. Trademaster is too powerful.
Gabe veers into his enemy and discovers the truth. Trademaster is no mortal, but a powerful force that feeds off the corruption of the world around him. It is that which sustains him. Gabe uses the knowledge he has, how Mentor is free from Trademaster's curse, the fact that Einer, though crippled, has lived a good life and been loved by a beautiful woman and how Claire gave up everything to find her son. Now that Gabe knows the truth, he declares that he and his mother will love each other always. With each proclamation of hope and bad things working out for good, Trademaster weakens until he disappears.
Jonas falls asleep while holding vigil by Claire's deathbed. At dawn, her bed is empty. He finds Claire restored to her younger self. She stands in the doorway, watching the morning break through the clouds. She tells Jonas that she sees the sun. He looks past her, and sees Gabe walking toward the hut.