Takakura, a former detective turned criminal psychology professor, relocates to a suburban neighborhood with his wife, Yasuko. They seek a fresh start after Takakura’s final case went tragically wrong, but his curiosity is piqued when a former colleague asks for his insight on a cold case involving a missing family. Takakura’s interest in the case intensifies as he uncovers disturbing details suggesting that this unsolved mystery might be more complex and closer to home than he initially thought. Concurrently, Yasuko begins to feel uneasy about their enigmatic and unusual neighbor, Nishino, who exhibits increasingly erratic behavior.

As Takakura continues to delve deeper into the mystery, he discovers unsettling connections and inconsistencies that point toward a chilling truth. His fascination quickly turns to obsession, putting a strain on his marriage and leading Yasuko to form a dangerous and uncertain bond with Nishino. Secrets from the past and present unravel, intertwining the lives of all involved, and steering them toward a shocking and ominous revelation.