When former detective Ryosuke Kanzaki's life hit rock bottom, a strange invitation from the mountains dragged him into a more terrifying whirlpool.
Michiko Kazama, the widow of a mysterious rich man, invites Ryosuke to her secluded mountain residence in Nagano Prefecture, the "Spider Web Mansion". The reason is irresistible: this twisted building shaped like a giant spider web contains the secrets of his late father from the Showa era.
After arriving, Ryousuke found that there were other invitees: the Kazama family members had their own agendas - Michiko, who controlled everything but was tired and cold, the eldest son Masahiko, who was full of resentment towards his late father, the youngest daughter Ayano who could "predict" strange events, the alienated and silent second son Masaki, and several outsiders with their own purposes.
Thick fog blocked the mountain road and communications were completely interrupted. The maze-like building itself seems to exude malevolence. When a depressing dinner turns into a family conflict, a piercing buzzing scream pierces the dead silence in the middle of the night, and the entire mansion is immediately plunged into absolute darkness.
When the lights go out, danger comes quietly. Is the murderer among the people bound by the spider web? What murderous potential does the shadow of the Showa era bring? Ryousuke must solve the mysteries in this deadly architectural maze and uncover the hunters in the darkness, otherwise he will become the first victim of the spider web.
