The following version of this book was used to create the guide: Moreno-Garcia, Silvia. Mexican Gothic. Del Rey-Penguin Random House LLC, 2020.

Moreno-Garcia’s novel is narrated in the third person and follows Noemí Taboada, a young woman who travels to the family residence of her cousin’s husband, where she investigates strange occurrences.

The novel opens in Mexico City, where Noemí’s father summons her home from a party. He has received a letter from Noemí’s cousin, Catalina, who claims the man she recently married, Virgil, is poisoning her. Virgil has also written, saying Catalina is unwell but recovering. Noemí’s father asks her to investigate the situation at the home of Virgil’s family, the Doyles.

In the town of El Triunfo, Noemí meets Francis, Virgil’s cousin, who drives her to High Place, the Doyles’ house. There, Noemí meets Francis’s mother Florence, a woman with a cold demeanor. Catalina tells Noemí she has had tuberculosis and does not remember what she wrote in her letter. At dinner, Virgil’s father, Howard, comments on Noemí’s dark skin, and speaks to her about eugenics and the role of beauty in natural selection.

The next day, Francis tells Noemí more about the Doyle family, who is of English ancestry and used to operate a silver mine. In the High Place cemetery, Noemí sees a statue of Francis’s great aunt Agnes. Francis explains that Agnes died during an epidemic that killed many of the miners. When Noemí visits her cousin again, Catalina seems disturbed and says the walls speak to her. She asks Noemí to obtain medicine for her from Marta Duval, a healer. Noemí meets Dr. Cummins, the family physician, who claims tuberculosis has caused Catalina’s mental symptoms. That night, Noemí dreams of golden mushrooms sprouting from the wallpaper and a golden woman.

In town, Noemí visits Dr. Camarillo, a local physician, to arrange for a second opinion on Catalina’s condition. She finds Marta Duval, who agrees to make the medicine for Catalina but warns Noemí that the Doyle place is haunted. Marta tells Noemí that Ruth, Mr. Doyle’s daughter, shot several members of the family before shooting herself, and that Florence’s husband, Richard, was found dead in a ravine.

Back at High Place, Howard tells Noemí about his wives, Agnes and Alice, who were sisters and his cousins. Noemí later has a nightmare in which Howard is undressing her before he seems to change into Virgil.

When Dr. Camarillo examines Catalina, he concludes she needs psychiatric attention, but Virgil refuses to move Catalina for care. Meanwhile, Noemí begins to spend more time with Francis and to entertain ideas of romance with him.

Noemí dreams of Ruth shooting someone else and then herself. She wakes up in a hallway with Virgil, who tells her she has been sleepwalking. The next day, Noemí picks up Catalina’s remedy. Marta tells Noemí that Ruth was in love with a man named Benito, but Howard arranged for her to marry her cousin Michael instead.

After Catalina takes Marta’s medicine, she falls into convulsions, but recovers. Virgil and Florence are angry at Noemí for having procured the medicine, which Florence claims, with Dr. Cummins’ backing, was an opium tincture. However, Francis tells Noemí that Catalina already had a similar reaction to the same remedy, and warns her to leave High Place. Virgil later apologizes to Noemí for being upset with her, and admits he married Catalina because his father is dying and wants to secure the bloodline. In the meantime, Noemí has dreamt of a woman giving birth to an egg-shaped lump that explodes into golden dust.

Catalina gives Noemí a diary entry of Ruth’s, which inspires Noemí to ask Francis if he thinks the house is haunted. He tells her again to leave High Place. Later, Noemí dreams that Virgil is sexually assaulting her and that she is wrapped in a shroud in a coffin. She begins to see mold on the wallpaper move, and decides to leave the house. After what is supposed to be her last dinner there, Florence and Virgil force Noemí to kneel before Howard while he kisses her. She has a vision of a man named Doyle among people who have a life-saving medicine.

When Noemí wakes up, Francis tells her the Doyles can bond with a fungus that gives them powers. To maintain these powers and obtain immortality, Howard impregnates female relatives and migrates into the bodies of men in the family. Noemí’s dreams and visions are caused by “the gloom,” a consciousness that controls the house and its inhabitants through the fungus. She appears to be compatible with the fungus, and the family wants her to marry Francis. Francis says that Howard will attempt to migrate into Virgil’s body soon. He and Noemí plan to escape at this time with the help of Marta’s tincture, which provides resistance against the Doyles’ powers.

After Francis and Noemí’s wedding, Virgil tells Noemí he knows about her plan and tries to rape her. She pushes him, causing him to hit his head, and runs to Catalina’s room, where Mary, a maid controlled by the Doyles, tries to strangle Noemí. Francis intervenes and Noemí slashes Mary’s throat. Florence, holding a gun, forces Noemí, Catalina, and Francis into Howard’s room, where Howard is to migrate into Francis’s body. Catalina stabs Howard with a scalpel several times. Francis struggles with Florence and shoots her in the process before escaping with Noemí and Catalina.

The trio flees to a chamber beneath the family crypt. Noemí discovers Agnes’s corpse there and understands Howard is using her mind to control the gloom. Virgil appears and fights with Francis, but Noemí sets the corpse on fire, which weakens the men, and Catalina stabs Virgil in the eye. Noemí and Catalina help Francis out of the crypt and they leave High Place as it burns. The novel ends with Noemí and Francis in bed together in a room in El Triunfo, speaking of a future in Mexico City.