When Claire turned 12, she was assigned to be a Birthmother. Now, at 14, she’s blindfolded and in labor with her first Product (the word used by this community to refer to babies). Due to complications, the Product is born by C-section, and Claire is reassigned to work at the community’s fish hatchery.
Claire is overwhelmed by loss and grief. Everyone in her community is content and superficial, and nobody seems to feel love for anyone else, let alone newchildren (newborn babies). Eventually, she begins visiting the Nurturing Center, ostensibly to volunteer but really so she can see her son, Thirty-six. Thirty-six doesn’t sleep well, so at the Ceremony, he isn’t assigned to a family. The Nurturing Center will care for him another year, and a kind Nurturer takes him home at night. Claire begins wondering what it would be like to travel on the river with the supply boats that come every so often—but wondering such things isn’t allowed in her community. At the Ceremony, the Nurturer’s son, Jonas, is also “selected” to be the “Receiver,” though nobody understands what this means.
As the months pass, Claire continues to visit Thirty-six. Claire begins to understand she’s the only one in the community who hasn’t been taking pills (Birthmothers don’t take them, and Claire was never asked to start after being reassigned). The pills, she realizes, rob people of their emotions—this is why everyone is just content. She vows to never give up her emotions and, for that matter, her love for her son.
As the next Ceremony approaches, Claire learns that Thirty-six is still not sleeping through the night, so he again won’t be assigned. The Nurturer won’t tell Claire where the chubby toddler is going, though. However, the next night, Jonas runs away with the baby. Claire escapes the community on the supply boat, intent on finding her son.
Claire has no memory of what happens between then and when fishermen rescue her from the sea. They take her to Alys, an elderly woman who functions as a healer and midwife. In this society, there’s no modern medicine or electricity—but people have emotions. Claire learns to feel, learns about colors, and learns to not be afraid of animals. She befriends a young man named Lame Einar, who years ago successfully climbed up the steep cliff face—the only way out—and climbed back down again, mutilated.
Over time, and particularly as she assists Alys at births, Claire’s memories come back to her. She remembers that she had a son. Knowing she must find him, she asks Einar to help her train to climb out of the community by going up the cliff, as she’s too afraid of the sea to leave by boat. With his help, she spends the next five years training—and she and Einar fall in love in the process. However, Claire knows she must leave to find her son, so when she’s ready, she spends a full day climbing. At the top, she waits for Trademaster, a frightening man. In exchange for her youth, Trademaster agrees to take her to her son, whose name is Gabe. Claire suddenly becomes elderly.
Fearing that eight-year-old Gabe won’t understand that she’s his mother, or that he might be embarrassed by her, Claire decides not to tell him who she is when she arrives in his village. She spends the next seven years watching him from afar. But Gabe is curious about where he came from. He doesn’t believe Jonas—now a married father in his 20s—that where they came from, babies were products and their birth mothers weren’t allowed to love them. This is partially because Gabe has memories of a woman who did love him. He begins to build a boat, which he plans to use to sail up the river to his former community and find his mother. Claire watches him, but because Gabe doesn’t know who she is, she makes him uncomfortable.
Knowing she doesn’t have long left to live, Claire approaches Jonas to tell him her story so that one day he can tell Gabe. Jonas is horrified to hear that Trademaster is still lurking: almost a decade ago, Trademaster corrupted the village by facilitating Trade Mart, where people would trade away their “true selves” in exchange for frivolous things (which Trademaster could give them because of his power to grant outlandish wishes in return for something valuable). It was only when a young boy named Matty sacrificed himself that Jonas, then the leader of the village, banished Trademaster and helped the village become welcoming and kind again. They decide they must tell Gabe.
Gabe, however, is trying and failing to launch his boat into the river for a practice run with his friends’ enthusiastic but unwanted help. Embarrassed and disappointed by the boat—but proud of the paddle he carved, which was very effective—he follows Jonas home. Jonas tells Gabe that Gabe likely has a “gift,” and that soon, he’ll need to use it to kill Trademaster. Exhausted, Gabe goes to bed, and they plan to continue the conversation in the morning.
In the morning, though, Jonas is gone: he’s with Claire, who’s dying. Gabe decides to tell Jonas’s wife, Kira, that he does have a gift. He can veer, or enter another person’s perspective. He also tells her about his desire to find his mother. Then, he joins Jonas and Claire. Gabe is derisive and disbelieving when Jonas tells him that Claire is his mother and that she traded her youth to Trademaster. Gabe only believes when they ask Mentor, the village’s teacher, to tell Gabe about how he traded away his honor in exchange for being handsome. Gabe suspects that if he can somehow kill Trademaster, he might be able to reverse Claire’s trade—after all, Mentor returned to his normal, honorable self.
Jonas’s gift is to “see beyond,” and he uses it to pinpoint Trademaster’s location on the other side of the river. Gabe takes his paddle and wades into the rushing river—but when Gabe has the thought that he can’t kill anyone, the river seems to slow and the moon comes out from behind a cloud. Focusing on all his friends who carved their names into his paddle, Gabe completes the crossing. He meets Trademaster on the other side. Trademaster tries to offer Gabe a trade: a boat, a sunny day, and Claire on the boat. Gabe refuses and instead, he veers into Trademaster. Seeing that Trademaster isn’t human (he’s pure evil in a human form) and that he lives on the satisfaction he derives from seeing people suffer due to his trades, Gabe tells Trademaster that Mentor is honorable again, Lame Einar is happy, and that he and Claire found each other. Trademaster disappears into nothing, and Gabe buries what’s left and marks the spot with his paddle.
As dawn breaks, Claire is a young woman again. She stands in the door of her cottage as Gabe comes up the walkway.