Elspeth recalls when she was nine, and the current Rowan King’s Physicians came looking for infected children (those affected by the god-like Spirit of Wood’s mist) at her aunt Opal and uncle Tyrn’s (the Hawthorns’) home. She ran at her aunt’s urging, but hit her head and lost consciousness; beforehand, she asked the dark creature in her head, the Nightmare, for help. When she woke up, she was safely in a forest.

Eleven years later, Elspeth and her cousin Ione travel through the kingdom of Blunder on her way to her father Erik’s house. They avoid the Rowan King’s Physicians and 13 Destriers (elite soldiers), who seek infected at the Rowan King’s command, and eventually make it to Spindle House. Though Elspeth was infected when she was nine, her family believes she lacks magic, and she has never corrected them. At her father’s home, she is treated coldly by her stepmother, Nerium, and half-sisters, Nya and Dimia. Though it is Elspeth’s nameday and her father seems pleased to see her, Nerium waits until they’re alone to remind Elspeth that she was sent to the Hawthorns’ as she has no place in the family. Elspeth leaves without notifying anyone, arguing with the Nightmare, who wanted her to stay and defy Nerium. When Ione does not follow her, Elspeth walks through the forest to the Hawthorn estate, clutching her crow’s foot, her charm against the Spirit’s mist.

Elspeth recalls how she came to host the Nightmare in her mind: One night, after her fever broke from infection, she spied on her uncle Tyrn—who had a bloody sword and two Providence Cards in hand. One Card was the Nightmare Card, which grants telepathy. Enthralled by its art, young Elspeth touched the unattended Card and fainted. She woke to the Nightmare manifested in her mind. He did not haunt her as The Old Book of Alders suggested, instead making her stronger and faster whenever requested; he also grants her the ability to see Providence Cards. Elspeth keeps the Nightmare a secret.

In the present, Elspeth is attacked by two highwaymen, one of whom uses a dagger with an ivory hilt. When they ask her who she is, she pretends to be a maid at her uncle’s estate. They press her about her uncle’s Providence cards, but she calls upon the Nightmare, and he imbues her with power. Elspeth strikes at the highwaymen and manages to run to her uncle’s estate, her veins burning with black ink.

The next morning, the Hawthorns receive an invitation to the Equinox celebration. Though her cousins Ione, Lyn, and Aldrich are excited, Elspeth plans not to attend, and her aunt Opal agrees because of the Hawthorns’ debt. Tyrn plans to pay this debt and negotiate other benefits by exchanging his Nightmare Card. Later, Elspeth picks up her mother Iris Whitebeam’s old copy of The Old Book of Alders, and remembers her mother and aunt’s explanation of the 78 Providence Cards (with 12 variants): 500 years ago, the deified Spirit of the Wood was worshipped by the kingdom of Blunder, who honored her by taking on the names of trees. The Shepherd King had been particularly favored by the Spirit and made the Providence Cards to share magic with the world. He bargained away personal possessions to make the Cards, but once the Deck was complete, people revered the Cards more than the Spirit—who spread mist to lure people back to her. The mist infected children and gave degenerative magic to those who survived infection. The Shepherd King bartered with the Spirit and upon dying, left behind The Old Book of Alders with instructions on how to lift the mist—which comprise collecting 12 Providence Cards to form a Deck and sacrificing an infected. He himself was never able to complete this ritual because he bartered away his most precious card—the Twin Alders—for knowledge of the ritual.

Later, Elspeth finds her aunt Opal in the garden with a letter from her father Erik. He asks that Elspeth attend the Equinox celebration. Knowing her stepmother Nerium would hate her presence and that she would likely encounter Alyx Laburnum (with whom Elspeth shared a kiss), Elspeth hesitates. She does not know how her degeneration will affect her, and worries it will manifest in front of the Rowan King or cause a fatal illness, like it did her mother. That night, she has a dream: Elspeth is in a room where an old man with yellow eyes and gold armor sits on a stone. Realizing this scene is the Nightmare’s subconscious, the dream quickly shifts to her uncle Tyrn’s library, where the Nightmare is waiting for her. When she asks after the old man, the Nightmare leaves her with a riddle about a girl, a king, and the monster they become.

Elspeth and the Hawthorns travel to Stone, where the Rowan King rules. Along the way, she and Ione discuss the possibility of trading the Nightmare Card, reflecting on how, while 78 Providence Cards were made, only 2 Nightmare Cards exist. Ione believes her father wishes to acquaint her with High Prince Hauth, and while Elspeth is repulsed by the idea, Ione believes him better than his brutish rumors. The women argue over the matter, and at the Rowan King’s castle, Elspeth chooses to be housed with the Spindles instead of the Hawthorns.

That evening, Elspeth makes her way to the great hall, only to be accosted by Alyx Laburnum. Though she has avoided him for the last three years, Alyx still vies for her attention and tries to bring her to his family’s table. When the Destriers enter, she takes the chance to sit at another table. Elspeth ends up next to Emory Yew, the Rowan King’s youngest nephew, and Second Prince Renelm Rowan (Elm). Feeling nauseous, she leaves the table, but Emory follows her under the guise of escorting her to her room. When they near a staircase, he grabs for her arm and, as if in a trance, tells her that he sees her—his yellow gaze hateful, and her fingers suddenly covered in blood. Elspeth tries to leave, but is ultimately helped by a handsome man who tugs Emory away and sends him back to the hall. She recognizes this man as Ravyn Yew, Captain of the Destriers and Emory’s older brother. He is suspicious of her, as he has only ever seen her half-sisters, but escorts her back to her room.

The next day, Elspeth is woken by her half-sisters, who wish to gossip about Emory—whom she learns has a bad reputation. Later, during a garden walk, she finds her aunt Opal, and they discuss the possibility of Emory being infected, and how many parents want to spare their infected children from the Rowan King’s dungeon. She sees Ione and the Maiden Card in her possession. Elspeth confronts her about the Card and her presumed meeting with Hauth. When Ione defends Hauth, Elspeth implores her to refuse him and the Maiden Card—which grants beauty at the cost of emotions. Ione asks that Elspeth let her make her own decisions. Upset, Elspeth wanders into the woods. As she argues with the Nightmare over Ione, she is discovered by Ravyn, who possesses the second Nightmare Card.

Ravyn asks why Elspeth was in the forest 15 days ago. She recognizes his dagger and realizes he is one of the two highwaymen who attacked her. She tries to deflect, but he is persistent. Elspeth runs, but Ravyn’s Nightmare Card asks that she wait. Ravyn tries to keep her quiet because the Rowan King and his men are on a nearby hunt, but she draws on the Nightmare to kick him. Her Nightmare tells her that she cannot trust the Rowan King, and she eventually quiets. When the Rowan King and his men are gone, Ravyn discovers the black ink that marks Elspeth as an infected. He assures her that he won’t harm her, that he only wishes to know about her magic. She follows him on the condition that they avoid the gardens, as the women there possess Providence Cards. Ravyn asks how Elspeth knows about others’ Cards.

Elspeth and Ravyn make their way back to the castle through a servants’ entrance, and arrive at a locked room. He temporarily leaves her there, locking the door behind him. She consults the Nightmare as to whether or not to reveal her ability to see Providence Cards, and the Nightmare correctly guesses that Ravyn will want to test her magic. When he returns, Ravyn is followed by his Destrier sister Jespyr and a Physician named Filick Willow. Elspeth recoils at Filick, having spent years avoiding Physicians to hide her infection. When Filick questions her ability, she decides to tell a half-truth, stating she can see the color of Cards—as each of the 12 variants has a unique hue. Suddenly, Elm enters the room. Elspeth sees his Scythe Card—which grants emotional command of people—and he reveals he was the other highwayman who attacked her. Furious, she refuses to answer further questions with Elm in the room.