Kang Min, Kam Woo-sung, awakens alone in a dark forest and immediately notices a secluded cabin nearby. When he enters the modest home, he confronts a brutal, bloody scene: a man lies dead, hacked repeatedly with a sickle. Min then discovers his girlfriend Su-yeong, Kang Kyung-hun, stabbed and barely alive, muttering something about "spiders." The moment he tries to intervene, the killer emerges and bolts into the shadows, forcing Min to seize the sickle and give chase through the ominous woodland surrounding the Spider Forest. The pursuit turns chaotic as Min is knocked unconscious by a blunt blow to the face, leaving him dazed and directionless. He trails the killer into a road-side tunnel, but the moment he steps inside, a speeding SUV tears onto the scene, sending him sprawling and injuring him badly as he bleeds onto the pavement. The killer stands close, seemingly to taunt him, and Min stretches out his hand in a desperate bid to seize the intruder, only to fade back into darkness.
Fourteen days later, Min wakes in a local hospital with his head heavily bandaged. At his bedside, his friend Choi, a police detective, offers quiet support while also pressing him for answers about the murders. The startling truth begins to unfold: Min has become the prime suspect, his fingerprints found on the sickle and his tense relationship with the victims casting doubt on his innocence. As Choi seeks to protect his friend, he asks Min to recount everything leading up to the brutal acts. Through moments of clarity and sudden gaps, Min struggles to reconstruct the events, yet some memories feel out of reach or untrustworthy. Other details blur, leaving him unsure whether they happened in the waking world or within a dream. The boundary between reality and dream grows increasingly ambiguous as Min works to piece together a past that could clear his name, even as the mystery surrounding the killer and the strange testimony of those around him deepens.
In this tense, slow-burning narrative, the forest becomes a character in its own right — a place where every shadow hides a potential truth and every memory could be a trap. The film emphasizes atmosphere and psychological tension as Min grapples with fragmented recollections, a creeping sense of paranoia, and the relentless question of whether he is a victim, a perpetrator, or something somewhere in between. As the story unfolds, the search for answers leads to a chilling realization: the only way to prove his innocence may lie in confronting memories that refuse to stay linear or reliable. The tale remains steadfast in its neutral, matter-of-fact presentation while inviting viewers to weigh what can be believed when the mind itself becomes a maze.
