Hometown Legends S01E03 - Curse of the Sajin Sword

This story involved the making of the holy 'Sajin Sword' which was supposed to protect the royal family and the country. When the blacksmiths who were engaged in the making of the sword died under mysterious circumstances one by one, a government official named Yoon In was sent to the village to investigate. He did not believe in spirits but could not find any logical explanation for the blackened burnt corpses.