The city of Seoul was buzzing with life, as always. From the neon lights of Gangnam to the traditional architecture of Bukchon Hanok Village, Seoul is a city of contrasts. But beneath the surface, there was a dark underbelly that Lee Seung Gi knew all too well. Lee Seung Gi was a detective with the Seoul Metropolitan Police Department. He had been investigating a series of murders that had been taking place all over the city. Each victim had been killed in a different way, but there was a common thread that linked them all together: they were all young, single men. Lee Seung Gi sat in his office, surrounded by files and photographs of crime scenes. He had been working on the case for weeks, but he was no closer to finding the killer. He sighed and rubbed his tired eyes, wondering if he would ever catch the murderer. Suddenly, his phone rang. It was his partner, telling him that there had been another murder.