Jude was only 7 when Madoc, a faerie and the High King’s general, came to her house looking for his wife and daughter. Jude’s mother had faked her death and fled Faerie with Jude’s older sister, Vivi. She married a mortal and had twin daughters, Jude and Taryn. In a fit of passion, Madoc killed Jude’s parents. He then took Jude and her sisters to Faerie to raise as his own daughters.
Vivi, being half-faerie, fits into the new world easily, even though she loathes it. Jude and Taryn have always been outcasts and afraid, even though they are protected by Madoc’s position. There are only two ways Jude and Taryn will ever have a permanent place in Faerie: They must marry a faerie or be asked to serve because of some great skill.
Now that they are 17, Taryn hopes to marry but Jude wants to become a knight. She admits that even though Madoc killed her parents, he has treated her as a daughter and she has come to love him.
Madoc has insisted that Jude and Taryn be raised like one of the Gentry. They attend dances at the High Court and lectures with the children of nobles. It has not been an easy life as many faeries hate mortals — especially the youngest son of King Eldred, Cardan. He and his friends — Locke, Valerian and Nicasia — regularly torment Jude and Taryn. Jude uses her anger to fuel her desire to become a knight. She wants to best them.
Madoc informs his daughters that King Eldred is planning to abdicate his throne in favor of one his children. Balekin is the oldest, but prone to debauchery. Princess Elowyn is next in line, but she is more interested in artistic endeavors than ruling the kingdom. Prince Dain is a warrior and considered the king’s choice to succeed him. Madoc assures his family he has a plan to ensure their futures once the new king is crowned at the autumn solstice.
Jude is furious when Madoc refuses to let her fight for a knighthood at the upcoming Summer Tournament. Jude takes out her frustrations on Cardan and his friends, and they retaliate against her. Vivi tries to cheer her sisters up by using her magic to take them to a mall in the mortal world. She wants the girls to move in with her and her girlfriend, Heather, but Jude and Taryn want to stay in Faerie.
After the first skirmish at the Summer Tournament, Cardan finds Jude and insults Taryn, sparking Jude’s anger. As the second skirmish begins, she fights viciously, attacking Cardan and Valerian. Her side wins the game.
Cardan is furious and threatens Jude unless she begs his forgiveness. She refuses, vowing to spend her life defying him. Locke, one of Cardan’s friends, comes to her aid. He tells her that she gets under Cardan’s skin like a splinter and encourages her to continue.
Jude returns home alone and is met by Prince Dain, the heir apparent to the Faerie throne. He offers to make her a spy within his court. If she accepts, she will live a life of danger, but she will also have the protection of the future king. As her biggest fear is falling under a Faerie spell and being forced to humiliate, or even kill herself, he offers to put a formal geas of protection on her. This will keep any other faerie from enchanting her.
Although the geas will protect her from a faerie spell, it cannot keep her from the effects of eating faerie fruit, which Valerian forces her to eat the following day. The fruit makes her delirious and open to any suggestion the faeries give her. When instructed, she takes off her clothes.
Cardan demands she kiss his feet, but Locke stops her. Cardan then pricks her finger with a pin. She sucks the blood from her fingertip, and the salt in her blood begins to dispel the effects of the fruit. Locke walks her home, wrapped in a blanket. Before he leaves her, he asks to see her again.
That night, Jude goes on her first spying mission for Prince Dain. She is to find evidence of treason in Prince Balekin’s home. She does not have to hide herself, as mortals are used as slaves and barely seen by most faeries. In a library, she finds a note about poisonous mushrooms. She makes a copy of it then hides as Balekin and Cardan enter.
Jude watches as Balekin has a servant whip Cardan for disappointing him. For the first time, she has a small amount of pity for him. Later, she brings the note she found to Prince Dain. He recognizes the handwriting as Queen Orlagh’s, Nicasia’s mother. He suspects Balekin of getting the mushrooms to poison him. Although she cannot be compelled by any other faerie, Dain forbids her from ever speaking or writing about what she knows and learns in Dain’s household. She is introduced to Dain’s other spies; they will teach her their tricks so she can improve her skills.
Exhausted from her work as a spy, Jude falls asleep in class. Valerian knocks her out of her chair after the other students leave the tower. He orders her to throw herself from the window. If she were not protected by Prince Dain’s geas, she would have to obey him, killing herself at his request. They fight, and Jude wounds him with a dagger. She flees the tower, and Locke walks her home.
He asks her to attend a party that night, and she agrees. He tells her that his father abandoned him and that his mother died soon after having an affair with the High King. When she became pregnant with the king’s child, she was poisoned with mushrooms. Jude and Locke share several passionate kisses. He offers her one of his mother’s dresses to wear at his party that evening, and she agrees. She stays the night in his bed.
When Jude gets home the next day, she finds a golden acorn in the pocket of the borrowed dress. Inside is a message from Locke’s murdered mother, asking the reader to protect “him” from the intrigues of the court. Jude realizes that the first note she had found about mushrooms may actually have related to Locke’s mother and not an attempt on Prince Dain.
The night before the coronation, Valerian sneaks into Jude’s room and tries to murder her. She kills him in self-defense and buries the body near the stables. The coronation of the new king turns into a blood bath when Prince Balekin and Madoc stage a rebellion. Prince Dain is killed.
Balekin needs a member of his family to place the enchanted crown on his head, but he, Madoc or Prince Dain’s spies have killed all of them. Prince Cardan is the only relative to survive and so the only one who can crown Balekin. Jude finds her nemesis, drunk and disorientated, and helps him escape the palace and the bloodshed. She knows that having Cardan in her possession is the only thing that gives her power in this world.
Cardan, afraid for his life, tells the truth about Prince Dain. Dain poisoned the king until he grew too tired for the crown. And he poisoned his preborn son so that he and the mother died. Jude understands that she must uncover why Madoc helped Balekin in this plot. Once she has all the pieces, she can decide what to do with Cardan. She leaves the prince with the other spies and heads home.
Once home, Jude discovers that Locke has also been involved with her sister Taryn and has asked permission to marry her. Taryn had to prove her loyalty to him by keeping their relationship secret from Jude while he toyed with her affections. Jude is prevented from killing Taryn in a duel by a spell cast by their sister, Vivi.
Madoc then questions Jude about Cardan’s whereabouts. He promises she can have anything she ever wanted if she would turn Cardan over to him. Before Jude leaves the house, she talks with her stepmother. Jude learns that her stepbrother, Oak, is actually Prince Dain’s child, thought to be poisoned with his mother.
In truth, Jude’s stepmother cut the baby from her friend’s womb to save his life. She and Madoc have raised him as their own son. Jude knows that Madoc plans to use Oak to gain more power in Faerie. He will rule as regent until Oak is old enough to reign. Jude’s stepmother begs her to stop the plan as she fears Oak will be killed in the power struggle, and she loves the boy.
When Jude returns to Prince Cardan she finds he has charmed the spies she left to guard him. They are drinking and playing cards. Furious, she drags him into another room to question him. As she has a crossbow aimed at his heart, and because faeries cannot lie, she finally learns the truth. Cardan acts like he hates her because he is infatuated with her. Jude makes him swear an oath that he will serve her for a year and a day.
He will crown Oak king, and then Jude and Vivi will hide their brother for his safety. However, Jude believes her brother will need more time away from Faerie before he can become a decent king, so she tricks Cardan into taking the crown.
Cardan is furious. He never wanted to rule. He promises to have his revenge on Jude. She and Vivi magic Oak to the mortal world where Vivi will raise him with her girlfriend. Jude returns to Faerie where Cardan reminds her he must follow her for only a year and a day. He plans on being a useless king and expects her to rule the kingdom and contend with all those who seek to overthrow him.