In the heart of Seoul, Detective Jeong Yunho finds himself thrust into the depths of darkness as he embarks on the chilling pursuit of "Nightshade," the city's most sinister serial killer yet. With a penchant for striking under the shroud of night, the elusive predator leaves behind a haunting trail of brutality, each crime scene a canvas of macabre artistry. As Yunho painstakingly unravels the cryptic clues, he becomes increasingly aware that the perpetrator may be lurking closer than he ever imagined. Could his target be hiding in plain sight, perhaps even entwined within his own life? With each twist and turn, the line between hunter and prey blurs, leading the good detective down a treacherous path where the greatest threat may lie within his own heart. Police Officer Yunho x Criminal OC