Mount Merbabu was supposed to be a dream hike for five friends seeking a quiet getaway above the clouds. But as thick fog rolls in and the trail mysteriously vanishes, they realize they are not alone on the mountain. Ancient local legends speak of unseen guardians and phantom spirits that wander the misty slopes after nightfall. When one by one the group begins to hear haunting whispers calling their names from the pitch-black wilderness, their peaceful trek turns into a desperate fight for survival. Will they make it down before the mountain claims them forever?