The fifth installment in the House of Night series opens in the aftermath of catastrophe. Zoey Redbird, a teenage fledgling at the House of Night, a boarding school for young people undergoing the transformation into vampyres, has fled campus with a small group of allies. An ancient fallen angel named Kalona has broken free from centuries of imprisonment beneath the earth, released when the school's corrupt High Priestess, Neferet, orchestrated events to spill the blood required to unlock his prison. Zoey's group now hides in tunnels beneath an abandoned Tulsa train depot, regrouping alongside Stevie Rae, Zoey's best friend and the first red vampyre—a fledgling who died and was reborn with scarlet tattoos and altered abilities—who leads a band of red fledglings, others who died and returned but have not yet fully transformed.
Zoey jolts awake from a nightmare in which Kalona visits her, calling her A-ya, the name of a maiden Cherokee Wise Women created from the earth centuries ago to lure and trap him. He insists Zoey is A-ya reborn and urges her to surrender, but Zoey resists and speaks the name of her Goddess, Nyx, shattering the dream. She recognizes that Kalona can reach her through sleep.
Unable to rest, Zoey replays the preceding hours. Darius, a warrior from the Sons of Erebus, the vampyres' protective order, extracted an arrow from Stevie Rae's chest after the fledgling archer Stark wounded her. With Stevie Rae nearly drained of blood, Aphrodite, who receives prophetic visions from Nyx, offered her wrist. The feeding saved Stevie Rae but created an Imprint, a magical blood-bond, between the two. Tensions surface when Zoey's friends meet the red fledglings. Among them is Kramisha, an outspoken aspiring writer whose poems, scrawled on poster boards in fluorescent markers, describe Kalona. Zoey names Kramisha the group's Poet Laureate. When Darius asks whether these are all the red fledglings, Stevie Rae avoids a direct answer, and Zoey notes the evasion.
Erik Night, Zoey's recently Changed vampyre ex-boyfriend, reports that an ice storm has knocked out cell service across Tulsa, isolating them. A text orders all fledglings back to the House of Night; Erik identifies the sender as Neferet. Zoey manages a brief phone call to Sister Mary Angela, a Benedictine nun sheltering Zoey's injured grandmother at the abbey, and confirms Grandma is safe. Heath, Zoey's human ex-boyfriend, arrives at the depot and reports that news outlets attribute the midtown violence to a gang, confirming Neferet's media manipulation. Outside, Heath begs Zoey to restore their Imprint, but she refuses. A Raven Mocker, one of Kalona's monstrous half-human, half-bird offspring, attacks. Zoey throws herself in front of Heath, and the creature's talons slash across her chest. She summons wind and fire to destroy it, then collapses.
Aphrodite casts a circle in Zoey's place, calling on Zoey's friends: Damien, who commands air; the Twins, Shaunee and Erin, who wield fire and water; and Stevie Rae, who channels earth. Heath feeds Zoey his blood, reviving her and re-establishing their Imprint. Darius delivers grim news: Without proximity to adult vampyres, Zoey will reject the Change and die. Before departing, Kramisha presents a prophetic poem listing five capitalized words, Night, Spirit, Blood, Humanity, and Earth, joined at a place of power to make Kalona flee. Zoey secretly passes Stevie Rae instructions to evacuate everyone to the Benedictine Abbey if given the word.
Zoey, Darius, the Twins, Damien, and Aphrodite return to the House of Night through the blacked-out city. Inside, Kalona insists on taking the wounded Zoey himself, and she faints against his cold chest. She wakes in the infirmary, healed, and overhears Kalona and Neferet plotting to sway the vampyre Council by breaking Zoey's loyalty to Nyx and exploiting her elemental power. When Darius intervenes to protect Zoey from Rephaim, Kalona's largest son, Kalona retaliates by slashing Darius's face with a knife. Before leaving, Kalona kisses Zoey, and the cold heat overwhelms her resistance.
That night, Kalona invades Zoey's dreams a second time, trying to seduce her. She breaks free, declaring she is Zoey Redbird, not A-ya. Stark appears at her bedside and reveals that sleeping beside a male companion blocks Kalona's dream invasions. They sleep side by side, and Zoey rests without dreaming. The next morning, Zoey finds a transformed school: Professors are compliant under Kalona's influence, Raven Mockers attend classes, and fledglings worship the fallen angel. Dragon Lankford, the fencing professor, covertly signals he is an ally. Aphrodite reveals through her Imprint that Stevie Rae lied about the number of red fledglings. Using Darius's phone, Zoey orders Stevie Rae to evacuate everyone to the abbey.
During Drama class, Kalona singles Zoey out, stoking jealousy among the fledglings and eroding their loyalty to Nyx. Near the stables afterward, Stark finds Zoey after she drives off a Raven Mocker with fire. She tells him she will not be his secret girlfriend, and Stark drops to one knee to pledge his Warrior's Oath, binding himself to her protection and choosing good over darkness. A flash of light engulfs Stark, and his crescent tattoo fills in with scarlet arrow designs: He has Changed into the second adult red vampyre. In the stables, Professor Lenobia, the equestrian instructor, declares allegiance and helps decode the prophetic poem. They identify the five who can banish Kalona: Zoey as Night, Stevie Rae as Blood, Aphrodite as Humanity, Zoey's grandmother as Earth, and Sister Mary Angela as Spirit. The place of power is the Benedictine Abbey.
Lenobia devises an escape using horses with flame-heated horseshoes and diversionary tactics. The group rides bareback through frozen streets: Damien conjures wind, Erin amplifies sleet, Shaunee heats the horseshoes, and Darius shoots pursuing Raven Mockers. They reach the candlelit abbey, where Stevie Rae, the red fledglings, Erik, Heath, and Zoey's grandmother have already gathered.
Kalona and Neferet arrive with Stark at the wheel, apparently compelled back into Neferet's service despite his oath. Neferet orders Stark to kill Zoey. Understanding that his oath means Zoey's heart is the mark he cannot miss, Stark fires at Zoey, knowing the arrow will redirect to his own chest. Zoey commands all five elements to destroy the arrow mid-flight, and the blast throws him to the ground.
The five women join hands: Zoey, Sister Mary Angela, Stevie Rae, Aphrodite, and Zoey's grandmother. Grandma addresses the Raven Mockers as sons of her ancestors, causing several to turn away in shame, then faces Kalona and recites a traditional Cherokee blessing. Every voice within the circle joins in, creating a unified expression of love. A blinding silver thread erupts from Zoey and wraps around Kalona and Neferet. Kalona staggers, wraps his arms around Neferet, and launches into the sky, propelled by the thread until both vanish into the clouds with the Raven Mockers trailing behind.
In the aftermath, Stark is found with a broken-arrow brand burned into his chest. He is not breathing, but when Zoey takes his hand, he gasps back to life. Sister Mary Angela warns that the conflict is not over, and Zoey affirms her Goddess will be with her. She feels a new tattoo burning across her scarred chest, another Mark of Nyx's favor, and looks up to see a crescent moon illuminating a statue of Mary, burning away the last of Kalona's hold on her heart.