You're trapped in a locked-room mystery where the culprit might be a witch, might be impossible, might be you're watching it wrong entirely. Every answer the show gives you is a trap designed to make you doubt the previous answer. By episode 13 it stops pretending to be a mystery and becomes something closer to psychological warfare, where the real puzzle isn't who killed the family, but whether any of this actually happened at all.
The Ushiromiya family arrives on isolated Rokkenjima for their annual gathering, expecting the usual tedious discussions about money and inheritance. Patriarch Kinzo is dying, and tensions run high as relatives circle like vultures. But something darker lurks beneath the surface. A century-old legend speaks of a golden witch named Beatrice who once walked these shores, and Kinzo has made a pact with her that defies explanation. When the family discovers an impossible murder, locked away from the outside world, they're forced to confront the possibility that the witch's curse is real. What follows is a nightmarish cycle of murder, revelation, and doubt. Each family member becomes suspect and victim, while the rules of logic itself seem to crumble. The real mystery isn't just who's killing whom, but whether there's any truth to be found at all when perception becomes unreliable and supernatural forces may actually exist. This is a story that makes you question everything you've accepted as fact.