As a boy, Nico once accompanied his mother on a research trip to investigate a stalled migration of monarch butterflies. One night, upon hearing her sneak out of their rented cabin, he followed her to a clearing in the forest where a famed mansion once stood. Paralyzed with fear, he watched his mother climb a staircase and vanish, along with the stairs and the strange glowing door at its peak. No one believed his story, and as he grew older, he too stopped believing it was real.

As an adult, Nico returns to his hometown to care for his ailing father. But something strange is happening to the town. There are unexplained power fluctuations, people are going missing, and, reportedly, phantoms are roaming the woods. When Nico finds his mother's field journal from the week she disappeared, including her account of the vanishing staircase, he begins to pick apart the mystery. All the tangled strings trail back to the same starting point: the gilded age family whose mansion burned down under mysterious circumstances in those very same woods where his mother vanished.

Equally a compelling mystery and a moving story of family and destiny, this speculative novel will spellbind readers of Emily St. John Mandel and Susanna Clarke.