The Heir is set in the fictional nation of Illéa, a monarchy that replaced the former United States after a series of global wars. Twenty years earlier, King Maxon dissolved Illéa's rigid caste system, a hereditary social hierarchy that ranked citizens from Ones (royalty) at the top to Eights (the destitute) at the bottom. He also changed the law of succession so that the firstborn child, regardless of gender, inherits the throne, making his daughter, Princess Eadlyn Schreave, the first female heir in the nation's history. Eadlyn was born seven minutes before her twin brother, Ahren.
Now eighteen, Eadlyn trains to become queen while her father struggles with the consequences of his reforms. Though the caste labels have been officially erased, discrimination persists, and riots break out as the younger generation discovers that old prejudices still block their access to jobs and marriages. Maxon decides he needs a distraction and proposes that Eadlyn undergo a Selection, the traditional process in which 35 suitors compete for a royal's hand in marriage. He and Queen America argue it will boost national morale. Eadlyn is furious, protesting that she does not want a husband and views the process as being shackled to a stranger. Ahren, who is already in love with Princess Camille of France, advises Eadlyn to use her bargaining power. She negotiates terms with her father: Contestants may leave freely, and if she finds no suitable match after three months, the Selection ends without a proposal. She announces the Selection on the weekly televised program called the Report, privately plotting to drive every suitor away.
Eadlyn draws one sealed name from each province. Her father privately reveals that his own Selection was rigged by his father for political alliances. The final name drawn is Kile Woodwork, son of Miss Marlee, one of the queen's closest friends, who has lived in the palace his entire life. Kile did not enter himself, and because Eadlyn read his name publicly, the selection cannot be reversed.
The suitors arrive. Several stand out: Hale Garner, who vows to prove himself daily; Ean Cabel, whose effortless confidence borders on unsettling; and Henri Jaakoppi, a Finnish immigrant who can barely communicate in English and requires a translator named Erik. Henri's warm, guileless smile keeps Eadlyn from dismissing him. The first public parade turns disastrous when anti-monarchy protesters hurl rotten food and insults, screaming about jobs and the persistence of the castes. Hale shields Eadlyn from projectiles while Henri tries to bat them away. Back at the palace, Ahren tells Eadlyn bluntly that her distant demeanor is making the Selection look lifeless and that the public needs warmth.
Eadlyn responds by eliminating 11 suitors on camera in rapid succession, dismissing some with a single word. The move backfires: A reporter presses her about her severity, and her mother privately tells her the public wants to see her falling in love, not issuing commands. Scrambling to recover, Eadlyn secretly arranges a staged kiss with Kile, promising in return to help him leave the palace so he can pursue architecture. Before the kiss, Kile shows her his designs, and Eadlyn is stunned by his hidden talent. Their kiss is far more affecting than either expected, and Kile returns for a second one. Eadlyn tells herself her smile is only for the cameras, though she does not quite believe it.
The kiss photos dominate headlines, buying the family breathing room. Eadlyn begins dating in earnest. She bonds with Hale, a tailor whose father died and whose mother struggles financially, over their shared love of fashion, though she flees when he asks to see her private sketches. She plays music with Baden Trains, a guitarist studying advertising, and finds a genuine spark. Ean takes her horseback riding and proposes a loveless marriage: He will never demand affection, and she can have total freedom in exchange for giving him a comfortable life. A date with Jack Ranger turns dangerous when he grabs Eadlyn's arm and refuses to let go. She breaks free and orders the guards to remove him. Ahren confronts the restrained Jack and knocks him unconscious.
Eadlyn hosts a televised quiz show testing the suitors on Illéan history, then sternly addresses consent, asking when it is acceptable to touch her without permission. Hale answers that it is never acceptable. A group cooking date with Kile, Fox Wesley, Burke, and Henri goes awry when Burke grows jealous of Henri's exquisite Finnish pastries and punches Fox. The fight escalates, knocking Eadlyn to the ground. Erik launches himself over the table to pull her to safety and stays with her until she calms, revealing his Finnish name, Eikko. Eadlyn feels a deep, unexpected connection to him. Burke is expelled, while Fox, whose father has cancer and whose mother abandoned the family, is allowed to stay.
On the next Report, Eadlyn designs her own dress and delivers her most charming performance yet, publicly praising individual candidates and bringing Henri and Erik onstage so Erik can translate Henri's thoughts on the responsibilities of a prince. Privately, Ahren reveals that multiple provinces are rallying to end the monarchy. Late that night, Eadlyn finds Henri cooking alone in the kitchen. He teaches her to make
omenalörtsy, Finnish apple fritters, and they communicate through gestures and fragments of English. She kisses him, and he holds her gently. She runs to her room still wearing his shirt and wrestles with her growing feelings, insisting that love makes people weak.
Erik warns Eadlyn that Henri's English will take years to develop, meaning real conversation without a translator is far off. Meanwhile, Baden confronts Eadlyn, accusing her of being selfish and two-faced, and quits the Selection. His press exposé, combined with a leaked quote from a visiting mayor, makes the entire Selection look staged. To shift the spotlight, Eadlyn proposes inviting Camille to the palace so the public can see Ahren's genuine love story. Camille's visit brightens the palace, but Eadlyn feels inadequate beside her gracious future sister-in-law. At a party for Camille, she shares a quiet, meaningful moment with Erik in the hallway and notices the connection deepening between them.
Afraid of losing Ahren to France, Eadlyn asks him to consider staying. Her words have the opposite effect. Days later, Gavril, the longtime host of the Report, delivers devastating news at dinner: Camille's mother has approved an immediate marriage, and Ahren has eloped. In a letter, Ahren explains he left because he knew Eadlyn would eventually convince him to give up Camille. He reveals that the anti-monarchy sentiment is focused specifically on Eadlyn and urges her to stop holding everyone at bay: She can be queen and still be a bride.
While searching for her parents, Eadlyn learns that her mother has had a heart attack. She arrives at the hospital wing to find her father sobbing in the arms of General Leger, a close family friend. Moments later, every remaining suitor files in to pray for the queen. Eadlyn looks at them and recognizes what has happened: Despite her resistance, these young men have claimed pieces of her heart. She looks at her father, devastated by the possibility of losing his wife, and understands that love is not weakness but the force that holds a soul to the earth. She resolves that when the Selection ends, she will have a ring on her finger. The story continues in
The Crown.