Azumi Harusaki, following her professor's recommendation, takes charge of a geological survey in a remote mountain village. Staying at an inn near the survey site, she begins to hear a gentle lullaby drifting from somewhere each night. Drawn to the melody, she peeks into a children's room deep inside the inn—and discovers a grotesque mass of flesh. Countless writhing tentacles spread out, filling the space with an eerie, unsettling presence.