Cha Woo-jin's first love, Seung-hee, was murdered 15 years ago. Obsessed with finding her killer, Woo-jin became a prosecutor and has since devoted his career to putting violent criminals behind bars. With ten days left before the statute of limitations on Seung-hee's case runs out, Woo-jin meets a 17-year-old high school girl named Jo Eun-bi who looks exactly like Seung-hee. Their meeting catalyzes a chain of events that lead Woo-jin nearer to uncovering the truth about the original crime, but Eun Bi's involvement in the investigation makes her the killer's new target.
