Set in Richmond, Virginia, a city whose history of slavery, Civil War violence, and Indigenous displacement haunts its landscape, the novel follows Erin Hill, a twenty-four-year-old struggling to break free from her codependent relationship with her charismatic, reckless ex-boyfriend Silas.
A prologue set three years earlier establishes their bond. Erin, her boyfriend Silas, her best friend Amara, and a quiet aspiring novelist named Tobias take acid and break into Hollywood Cemetery, where Silas leads them to a mausoleum. He claims he wants to perform a ritual to speak with the dead. Erin knows his true motivation: His mother died in a car accident when he was nine, and he was in the backseat. He has been chasing her ghost ever since. Inside the mausoleum, Erin writes "ERIN IS HERE" in permanent marker, a ritual she repeats throughout the novel to anchor herself to the present.
In the main narrative, Erin is on a blind date when Silas calls. His voicemail is three words: "Come save me" (32). She picks him up after he has broken out of rehab. He is barefoot, drenched, and erratic, nearly leaping from her car on the highway before vanishing into the woods. He reappears at her apartment at 3 a.m., and she lets him stay. Their dynamic has not changed: She takes care of him and cannot say no.
Erin and Amara plan an intervention that fails. Silas arrives visibly high, insisting he is not high but "haunted" (56). Erin shoves him out, screaming that he is dead to her. Days later, Silas is found dead of an overdose beneath a highway overpass, where he spray-painted "SILAS AND ERIN ARE HERE." Silas's younger sister Callie calls to blame Erin for his death. Paralyzed by guilt, Erin stays home calling his phone to hear his voicemail greeting.
Tobias reveals he was with Silas when he died and asks Erin if she has ever heard of Ghost, a drug derived from a rare mushroom called
Hebeloma sarcophyllum that allows users to perceive the dead. Erin drives Tobias and Amara to Shady Acres, an abandoned housing development near Hopewell, Virginia, where Tobias has chosen a half-finished townhouse as their base. He explains that a house without a history is free of preexisting ghosts and can serve as a vessel for the spirit they hope to summon.
They swallow Ghost in gelcap form and attempt a séance. The session appears to fail, but alone that night, Erin eats a raw Ghost mushroom and words begin appearing on the walls in Silas's handwriting: "I AM HERE," "FIND ME" (112). A second séance produces more dramatic results: Erin calls out to Silas and feels her body dissolve into the house. A silhouette steps from the shadows. Ectoplasm, a thick, living substance, pushes violently from her throat. Amara refuses to participate again, but Erin insists on continuing. During a third session, she hallucinates a gray, freezing ocean filled with churning bodies. She wakes on the floor. Tobias declares Silas is home.
Back in Richmond, Erin steals Tobias's remaining Ghost supply and doses alone. The consequences are catastrophic. She begins seeing ghosts everywhere: an elderly woman wrapped in plastic on her street, burnt ironworkers at her new advertising job, a warrior from the Monacan people, an Indigenous nation native to Virginia, at her father's birthday dinner. The spirits smell Ghost on her and crowd around her. She expels ectoplasm at work and vomits at the dinner table. She notices one of her wall tags has changed from "ERIN IS HERE" to "ERIN WAS HERE" (127), as if her grip on the living world is slipping. At Amara's going-away party, she flushes her last cap and vows to quit, but the visions persist. She also learns Amara had been sleeping with Silas after college, a betrayal that fractures their friendship.
Erin flees to the house in Hopewell, the only place she feels safe. Tobias has painted a blood sigil on the front door that keeps uninvited ghosts outside, and he has transformed the house into a drug operation and séance parlor with live-in followers. He coerces Erin into dosing again by leveraging her desire to see Silas, and the communion is ecstatic: A flame-like spirit enters her body and she relives Silas's memories. Tobias also forces her to kiss him in exchange for gelcaps, placing them between his teeth so she must take them from his mouth.
Erin begins losing time. She hallucinates domestic scenes with Silas. Messages from him spread across the walls like black mold. A faceless baby crawls from the drywall; Erin names it Lonnie and cares for it as their child. When a security guard discovers the operation, Tobias kills him. Erin manages a brief phone call to Amara before Tobias smashes the device. She escapes briefly but finds someone else living in her apartment. Feeling a physical pull dragging her back, she returns to the house.
Desperate to cross over permanently, Erin swallows at least five caps at once. Amara arrives to rescue her, having traced the earlier call, but a shadow attacks Amara, snapping her arm and throwing her against a wall. Erin experiences clinical death. Tobias's followers wrap her in plastic and dump her in a ditch along the interstate.
Erin claws free and is found by police. In the hospital, doctors discover multiple organ failure and a fungal infection in her bloodstream. She repeats a single declaration like a prayer: "I don't want to die" (267). She escapes the hospital and returns to the house one final time. She discovers that Tobias is actually possessed by Silas's ghost. Silas reveals the entire scheme was planned from the start: He needed Erin's emotional connection to make Ghost work, then took over Tobias's body after Tobias willingly offered it. He claims Erin herself killed Amara during the overdose. He offers her forever. She refuses.
During a mass séance, Silas's followers force a gelcap down Erin's throat. She flings the front door open and invites the hundreds of revenants, homeless ghosts with no vessel to inhabit, inside, breaking the protective seal. The ghosts flood the house, possessing users and driving them to mutilate themselves and each other.
Erin descends to the basement and finds three raised garden beds containing corpses that serve as fertile ground for the Ghost mushroom. The security guard lies in one. Amara lies in the second, still alive, mushrooms growing from her face, her eyes conscious. Silas's corpse fills the third, consumed by fungal growth. Erin splashes the planters with paint thinner and ignites them with Silas's lighter, then burns every occupied house in the development.
In the epilogue, set roughly a year later, Erin has completed rehab and founded Richmond Revenants Recovery, a support group for Ghost addicts. She tells her story at meetings, emphasizing that choosing life begins with four words: "I want to live" (297). Ghost is spreading nationally. Erin visits the rebuilt development, now renamed Greenfield. In the lawn, she spots a ring of mushrooms that turn toward her. She plucks one and pockets it, suggesting the cycle of addiction may not be over.