Jang-woo’s life revolved around his sister until her tragic murder shattered his world. During a ceremony meant to guide her spirit to the afterlife, he encounters a mysterious man who quickly flees. This encounter leads Jang-woo to suspect a local pharmacist, whom he starts to monitor closely. Despite his certainty that the pharmacist is the murderer, the townspeople dismiss his claims, as the pharmacist is known for his kindness. However, Jang-woo finds an ally in Si-eun, a woman possessed with the ability to foresee deaths. Together, they embark on a quest for justice, with Si-eun foretelling yet another impending murder.