Alejandra is a stay-at-home mother of three living in suburban Philadelphia. Her husband, Matthew, a director of sales, moved the family from Texas for his career, and Alejandra quit her data entry job to manage the household. She has no friends in the area and no sense of purpose beyond caring for her children: nine-year-old Catrina, four-year-old Will, and eighteen-month-old Elodia. She is in profound emotional crisis, plagued by intrusive thoughts of suicide and trapped in a loveless marriage.
One evening, while sitting beneath the shower in despair, Alejandra sees a white, amorphous form near the towel rack. A voice whispers, "You want to end it. Let me help you" (2). She refuses, and the figure vanishes, leaving a slimy residue on the glass. Despite her rational mind's resistance, something deeper tells her the presence was real. Matthew bangs on the door demanding dinner, oblivious to her anguish. When she once confided suicidal thoughts, his response was dismissive: "Look at everything you have" (7).
Alejandra was adopted at birth and raised in a strict Evangelical household in Texas. Her adoptive parents prioritized obedience over affection, and her adoptive father used corporal punishment. At eighteen, Alejandra broke from them when they refused to share information about her birth family. Years later, a DNA testing service connected her to her birth mother, Cathy Castillo, a general practitioner at a Texas hospital. Cathy explained that she became pregnant as a teenager and gave the baby up to pursue her dream of becoming a doctor. Cathy's own mother, Frances, abandoned the family when Cathy was young, vanishing without explanation. Alejandra and Cathy began meeting weekly, but the relationship was cut short by the move to Philadelphia. Cathy gave Alejandra a box of old albums from Alejandra's birth father, Rogelio.
Supernatural disturbances multiply. Alejandra glimpses a skull-faced woman in her rearview mirror after nearly causing a car accident. That night, Catrina asks for a bedtime story about La Llorona, the weeping woman of Mexican folklore who drowned her children and is doomed to wander the Earth. After hearing the tale, Catrina speaks in a hollow voice unlike her own: "No, I hope we live long enough" (22), then snaps out of it with no memory. Alejandra is also tormented by recurring dreams. In one, a half-creature in a white dress watches her drown. In another, brown women from different eras float in a cenote, a natural sinkhole sacred to the ancient Maya, their palms upturned as though poised to lend her their power.
The novel intercuts Alejandra's present-day story with historical chapters tracing a generational curse. In 1522, during the Spanish conquest of Mexico, an indigenous woman named Atzi, repeatedly assaulted by a conquistador and pregnant with his child, struck a bargain with a grayish-white supernatural creature. It would protect her firstborn daughter, Yaretzi, if Atzi surrendered the souls of her unborn twins, her own soul, and the binding of her bloodline's suffering to the creature forever. Atzi accepted. The creature seared a birthmark onto her forearm resembling a constellation, a mark that would reappear on future generations. Atzi cast herself into a cenote, her last thought a prayer that her descendants would one day find her spirit.
In the present, the creature appears in the children's paddling pool devouring a pigeon and hisses at Alejandra, "You're next" (49). She decides to seek help and finds Dr. Melanie Ortiz, a Mexican American therapist who is also a practicing curandera, a traditional healer combining indigenous spiritual practices with therapy. Alejandra confesses everything: the visions, the suicidal ideation, the loveless marriage, and the entity feeding on her self-hatred. Melanie takes the visions seriously and, over subsequent sessions, guides Alejandra through visualization exercises to release generational trauma. She also presses Alejandra to examine her marriage. Alejandra realizes Matthew's expensive gifts were instruments of control, not love, and that she surrendered her autonomy for material stability.
The crisis escalates when Catrina's school reports the girl has been telling her teacher that a woman in white eats birds at the edge of the playground, a detail mirroring Alejandra's own vision. Catrina reveals the creature tells her that her mother does not love her. Melanie advises Alejandra to build a home altar for ancestral connection and protection. Alejandra constructs it and purges the house of everything Matthew chose for her, recognizing how little of her surroundings reflects her true self.
Historical chapters reveal how the creature stalked earlier generations. In 1961, Alejandra's maternal grandmother, Frances, was trapped in an isolated military marriage in Texas, enduring infidelity and consecutive pregnancies. She heard the same taunting voice: "Wretched woman. Difficult woman. Dead woman" (126). Her mental state deteriorated until she took a bus to the Rio Grande, where the creature, wearing a white mantilla, stood beside her and urged her to jump. Frances stepped into the current. In 1978, teenage Cathy endured her pregnancy and gave baby Alejandra up for adoption. The creature, watching from the shadows, resolved to target the child when she grew up.
The creature now attacks openly, manifesting in Elodia's room and whispering about the scent of the children's purity. When Alejandra asks if it is La Llorona, it laughs: "No. Silly, human. You are" (168), implying that any woman consumed by pain becomes its vessel. It also attacks Melanie in her office and appears at Cathy's hospital among the newborns. Cathy flies to Philadelphia with family photos and heirlooms, including a picture of their ancestor Flor, a soldadera, or female soldier, who fought in the Mexican Revolution. Alejandra recognizes Flor as one of the women from her dreams.
Flor's backstory reveals a critical precedent. Widowed young, Flor joined the Revolution, befriended Colonel Amelio Robles Ávila, a transgender military officer, and became the lover of revolutionary leader Emiliano Zapata. After Emiliano was killed in an ambush and Flor was shot in the abdomen, the creature appeared and demanded her unborn child. Flor grabbed it by the throat and tried to pull it into her body to destroy it, recalling her mother Dorotea's teaching about transmutation. The creature escaped, but Flor survived, preserving a family altar with relics from the struggle and passing down a guiding principle: "We change the future by unloading the sorrow of the past. We sever the cord of generational curses" (xiii).
Armed with this ancestral knowledge, Alejandra forms a radical plan: She will feign surrender to lure the creature into vulnerability. She travels to Texas, first locating Rogelio at a flower shop, where he reveals she has a half-sister named Natalie. She then meets Cathy at the Redwood Inn, the same hotel where Frances once sought escape.
At Cathy's apartment, Alejandra fills a bathtub with water, herbs, and vials of each child's blood. She slits her wrist to lure the creature, which rises from a whirlpool and gloats that it will destroy her children. As it dives into her body to consume her, Alejandra plunges a knife into her own abdomen, trapping it. The spirits of her ancestors materialize: Flor, Atzi, Frances, and others from across the centuries. They push the creature deeper as Alejandra screams, "I accept love. My love. I am and they are all I need to complete me" (242). The creature is fully absorbed. Cathy enters and takes Alejandra's hand as she loses consciousness.
A separate chapter reveals the true origin of the La Llorona legend. In 1616, a desperate widow named Rosa—unrelated to Alejandra's bloodline—jumped into a river with her two young daughters, but the girls survived and were rescued by a kind landowner. Villagers, unaware the children lived, spun the tale of a grieving ghost. The creature adopted the persona, confirming it is not La Llorona but a parasitic entity from a destroyed realm that co-opted the myth.
In the epilogue, Alejandra recovers and tells Matthew she wants out of the marriage; he does not resist. Five weeks later, she passes a fist-sized blood clot containing the creature's final remnant. A single eye opens in the mass. She squeezes it until it pops and flushes it away, feeling the weight of generational sorrow lift from her body. She understands at last why she was born: "She had been born to kill this demon. Someone had to end the cycle" (259). Alejandra texts Melanie asking to be trained as a curandera, wanting to help others who may face similar forces. Catching her reflection in a glass door, she speaks to herself with love for the first time: "I see you now. I see you like no one else because we are one and the same and forever will be. And I adore you" (259).