In a rural village west of Bangkok, Mak Winai Kraibutr is conscripted and sent to fight in the Siamese-Vietnamese War (1831–1834), leaving behind his pregnant wife Nak Intira Jaroenpura. Mak is wounded and barely survives, and he eventually returns home to his beloved wife and their child.
A friend visits and finds Mak living with Nak. The villagers, knowing she had died months earlier, realize Mak is spellbound by her ghost. But those who attempt to tell him are killed in the night by Nak's ghost, who is desperate to stay with her husband. When Mak confronts Nak about the rumors, she lies and says the villagers disliked her after he left for the war. She claims they are also telling lies about their son not being Mak's. Mak believes her and lashes out at anyone who tells him she is dead.
Mak eventually discovers the truth. Crawling under their house one night to retrieve an item, he trips on something sticking up from the dirt. Curious, he digs it up and finds a corpse, making him wonder why Nak would always prevent him from going down there. Looking up through the creaks of the wood floor, he sees Nak sitting and brushing her hair. Dropping the comb through a crack, her arm eerily extends all the way to the ground to retrieve it. Mak covers his mouth to stifle a scream and continues observing Nak. Nak picks up her crying baby, who Mak realises is a corpse as well. A series of flashbacks reveal that Nak had a difficult childbirth and both mother and child died from complications.
Mak flees in terror to the local temple to hide. Nak follows him and attempts to win him back, but he is too frightened of her. The villagers attempt to drive out Nak, burning down her house and at last summoning an exorcist. Nak refuses to leave unless Mak returns to her. Mak pleads with her to leave to the netherworld. He loves her, but they can't be together since she is dead. He tells her that he is going to cut his hair and become a monk in order to pray for her sins and allow her spirit to find peace. She still refuses.
The kingdom's most respected Buddhist monk, Somdej Toh Dome Singmoree, intervenes and, in a tearful farewell, Nak repents, leaving her husband for this life. The monk has the centre of her corpse's forehead cut out, thus releasing her spirit, and makes a girdle brooch of it. The epilogue states it later came into the possession of Prince Chumbhorn Ketudomsak. It was thereafter handed down for generations, with its current owner unknown.
