In this lyrical, wildly inventive horror novel interwoven with Japanese mythology, two people living centuries apart discover a door between their worlds. October, 2026: Lee Turner doesn’t remember how or why he killed his college roommate. The details are blurred and bloody. All he knows is he has to flee New York and go to the one place that might offer refuge—his father’s new home in Japan, a house hidden by sword ferns and wild ginger. But something is terribly wrong with the no animals will come near it, the bedroom window isn't always a window, and a woman with a sword appears in the yard when night falls. October, 1877: Sen is a young samurai in exile, hiding from the imperial soldiers in a house behind the sword ferns. A monster came home from war wearing her father’s face, but Sen would do anything to please him, even turn her sword on her own mother. She knows the soldiers will soon slaughter her whole family when she sees a terrible a young foreign man who appears outside her window. One of these people is a ghost, and one of these stories is a lie. Something is hiding beneath the house of sword ferns, and Lee and Sen will soon wish they never unburied it.