In a remote Thai village, a young girl mysteriously dies after hearing a creepy "Tee Yod" chant. Years later, a family is terrorised by the same evil spirit possessing their daughter Yam`s body. Her brother Yak seeks help from a sorcerer to dispel the demon. After a dangerous journey to take Yam to the hospital, Yak is forced to shoot her to drive out the spirit that emerges from her mouth. However, even that cannot save her. He vows vengeance against this ancient evil force plaguing his family and the village.