The protagonist, Six, is a prophetess known as a Diviner in Aisling Cathedral in the Stonewater Kingdom, located in the land of Traum. The kingdom is made up of five hamlets: Coulson Faire, the Seacht, the Fervent Peaks, the Chiming Wood, and the Cliffs of Bellidine. As a child, Six was brought to the cathedral’s abbess as one of six foundling girls raised to be Diviners and to prognosticate through visions. When they arrived, their names were taken, and they were given a number. They have never seen themselves or each other, as they are forced to wear gossamer shrouds over their eyes. 

Six slips out of the cathedral’s ambulatory as a nearby sentient gargoyle lectures a fly caught in a spider’s web before freeing it. She passes through the courtyard that has five stone statues of hooded figures, each holding one of the five sacred objects of Traum: a coin, an inkwell, an oar, a chime, and a loom stone. Six feels as if the statues watch her, and she worries about angering them as she passes through the courtyard, through the orchard in which she picks an apple, and toward the stone wall. The five other Diviners are sitting atop the wall, waiting for the new king’s arrival at Aisling Cathedral. 

The other Diviners tell Six to hurry so that she doesn’t miss seeing the king. She quickly bites her apple and offers it to Five with the warning that it’s not sweet. Five throws it over the wall. The women watch as the king arrives with his retinue of two dozen knights, squires, and bannermen. Three thinks that the king brought so many men because he’s a child who’s afraid of Aisling and divination. The group of Diviners draws straws to decide who must dream and divine for the king; Six draws the short straw, which is what usually happens, as Six dreams the most.

The king, Benedict Castor the Third, rides with uncertainty, and his face is round with youth. The king calls out to the Diviners, followed by the knights calling and asking the women for favors or kisses. The retinue keeps moving, except for one horse, which stops to eat Six’s thrown apple. The knight atop the horse curses and removes his helmet. Six notes his sharp features, the golden hoops in his ear, and the charcoal smudged around his eyes. She asks the knight if the king brought so many knights because he is afraid of divination. The knight tells her that she and the other Diviners are the true spectacle.

The gargoyle that freed the fly earlier returns and tells Six to hurry inside so that they can begin the divination process. There are 23 gargoyles at Aisling Cathedral, and most rarely speak, except for this bat-like gargoyle. He calls everyone “Bartholomew” for an unknown reason and refuses to use his wings to fly. 

He leads Six into the transept at the center of the cathedral, where the spring lies. The spring smells of rotting flowers. The abbess is waiting, wearing a veil that covers her entire face and gloves that cover her arms. 

Six changes out of her dress and into the Diviner robe. She enters the viscous water of the spring, which rises to her chest. She looks up at the stained-glass windows that depict the five stone objects (coin, inkwell, oar, chime, and loom stone) and the flowery wings of a moth. The king and his knights enter the room, and the abbess begins the divination process. She asks King Benedict what he wishes to know, and he asks if the Omens favor him. The abbess hands Benedict a knife and tells him to begin.

Benedict cuts his palms, and the abbess guides his hand to Six’s mouth, commanding her to drink his blood. Six chokes it down before the abbess begins telling the story she always tells before divination. The five hamlets of Traum are Coulson Faire, the hamlet of merchants; the Seacht, the hamlet of scribes; the Fervent Peaks, the hamlet of fishers; the Chiming Wood, the hamlet of foresters; and the Cliffs of Bellidine, the hamlet of weavers. 

She tells the history of the hamlets, which were in chaos and overrun with dangerous sprites and lawless crime until the six gods came down to Traum. One day, a foundling child went to the tor in search of food and found the spring. He drank from the spring and fell into a dream where he saw the six Omens of Traum: the Artful Brigand and his coin, the Harried Scribe and his inkwell, the Ardent Oarsman and his oar, the Faithful Forester and her chime, and the Heartsore Weaver and her loom stone. The sixth Omen appears only as a moth and cannot be seen by Diviners but supposedly appears during birth or death. The knight from the road stands and leaves, interrupting the abbess before she continues her story.

Aisling Cathedral was built around the spring upon the tor, and foundling girls were brought to become the revered Diviners, also known as the daughters of Aisling, to dream and divine the future. The hamlets were united under a king as the Stonewater Kingdom, but the king was then and is still more supplicant than sovereign, never taking up the mantle of faith for personal gain by seeking the Omens and their objects. The abbess reminds them that they are all but visitors to the greatness of the Omens. Everyone repeats the mantra “ever but visitors” before Benedict gives Six his full name (18). Afterward, the abbess pushes Six beneath the water, drowning the Diviner as she commands her to dream.

Six awakens naked except for her shroud in another version of the cathedral, which is empty. She tells the Omens that she has arrived to divine for King Benedict Castor the Third. The floor gives way, and she falls onto a pile of coins. She senses that the abbess and gargoyle have dragged her out of the spring and placed her upon the chancel to continue dreaming. The abbess’s voice cuts through her dream and asks her what she sees. 

Six sees the Artful Brigand’s coin with the rough side up, and she announces a bad portent for the king. She falls again onto a carpeted floor and then gets up and walks before ink flows over her feet. She announces that the Harried Scribe’s inkwell is overturned and spilling, another bad sign. She falls again, landing atop a boulder and breaking her collarbone. She pushes through the pain to stand, feeling perverse pride in her ability to endure agony for the benefit of others. Her body is covered in cuts and bruises as she looks and sees the Arden Oarsman’s oar standing above a pool of still water—another bad omen. 

She then falls into a forest with trees whose bark seems like skin covered with eyes and sees the Faithful Forester’s chime ringing discordantly. She announces the fourth bad portent before she falls into the darkness. She sees nothing but the loom stone hanging from a frayed thread, the fifth and final bad portent. She hears a strange clacking sound getting closer to her until she hears the abbess call out to her. Six wakes with a gasp.

Six’s real name was Sybil Delling. She doesn’t remember who gave her that name or anything about her time before Aisling Cathedral. All she remembers is waking up as a child, sobbing in the spring. The abbess promised her love and care in exchange for 10 years of serving as a Diviner. Sybil agreed, and her name was changed to Six before the abbess drowned her in the spring. 

Six woke up sick, but the abbess held her close and told her that spring was magical and holy and that now Six was magical and holy, too. Six was reborn. The abbess then tied a shroud over Six’s eyes, and she has never since seen her own eyes or those of the other Diviners or the abbess. The Diviners are referred to only by a number, and they drown and dream to divine for the people of Traum. Six vowed to never forget her real name, the name she wants to use after her tenure at Aisling is over. However, lately, she’s forgotten.

The gargoyle comforts Six as she wakes up from her dream in the sacristy. She throws up the spring water, which frustrates the gargoyle because he just cleaned the floors. Six’s body is unharmed, but the pain of the cuts and broken collarbone lingers like a ghostly presence. She is thirsty and decides to go to the dining commons for water. The cathedral is built upon the tor, alongside a dining commons, a stable, the abbess’s cottage, the Diviners’ cottage, the gargoyles’ cottage, and a small stone cottage that remains locked and unknown to the Diviners.

When Six reaches the dining commons, an older female knight named Maude Bauer stops her, confused as to why she’s wandering around at night alone. Maude offers to get Six some water, but Six insists on getting it herself. When she enters the dining commons, Six finds the knight from the road shirtless and smoking something. Maude tells the other knight that Six needs water. The knight doesn’t seem to appreciate divination or think it’s special. Six realizes that he’s shirtless because he is tending to terrible bruising on his abdomen. King Benedict appears holding a flagon and thanks Six for the divination. When he sets down his flagon, Six can smell the rotting floral scent of the spring’s water. She throws up on the knight’s boots.

Six runs out of the dining hall, and the knight chases her barefoot. She and the other Diviners hide how sick the spring water makes them so that they don’t appear weak. The knight asks Six if she got sick from swallowing the blood or spring water, but Six refuses to answer. She asks him why the king stole spring water, but the knight refuses to say. He offers her petrified idleweed to smoke, claiming that it will help with the nausea, but she refuses. 

The knight expresses doubt in the Omens and the system of divination, which shocks Six. She defends divination as taking away the pain of the unknown. The knight introduces himself as Rodrick “Rory” Myndacious. Six smokes some of Rory’s idleweed and feels calmer and lighter. Rory asks about the shrouds that hide the Diviners’ eyes and the lack of their real names, but Six tells him that it’s a secret. He accuses her of thinking herself superior to others because of her role as a Diviner, which offends Six. She leaves without apologizing for getting sick on Rory’s boots.

Six hears One, Three, and Four return to the cottage around dawn. Four is upset because she had sex with a knight who turned out to be married. One was also intimate with a knight, and she reports that it was mediocre. Though the Diviners cannot leave the tor or have visitors in their cottage, there are ways to obtain bedmates. They can lie in the grass with people who visit the tor for divination, and the bolder Diviners sometimes sneak into the nearby hamlet of Coulson Faire for a night of fun. Six has had sex in the grass with two men and a woman, but none have satisfied her. She stopped taking strangers to the grass, but privately, she worries that she’s forgotten how to be human.

The abbess comes and checks on the Diviners, assigning One, Two, and Three to divine for the people coming to the tor and Four, Five, and Six to their usual tasks. When the abbess leaves, the Diviners fantasize about their lives after their tenures are over. Six expresses a desire to leave the tor, and Four immediately says that they should all go to Coulson Faire that night. Six plots to find an escort for them.

Six finds Rory, Maude, and King Benedict, whom the knights call “Benji,” in the dining hall. She tells Rory that she and the other Diviners want to go into Coulson Faire. She tells Rory that if he and some other knights don’t escort them, Six will tell the oft-violent gargoyles that the trio stole spring water. Before Rory answers, a gargoyle takes Six away to do her stonemasonry chores with her hammer and chisel. Six angrily does her work of breaking up stones, cursing Rory as she does so. 

She and the other Diviners then divine for the people who visit Aisling Cathedral to pay for portents. Feeling sick afterward, she comforts One with a story about what the Diviners will do after they’re free from Aisling. One sees something strange near the Diviner cottage, and when Six investigates, she finds a bunch of idleweed with a note from Rory instructing them to be ready by nightfall.