"From now on, I’m going to catch a serial killer. Live, in real-time" Woo Sang (KANG Ha-neul) is the number-one crime channel streamer on WAG, Korea’s hottest streaming platform, where only the top-ranked streamer takes all the donation earnings. Gaining massive popularity by analyzing unsolved true crimes, he dominates the platform—until controversy drags him into a sudden downfall. Determined to reclaim his top spot, Woo Sang begins a live broadcast tracking the infamous Hemline Serial Killer. As he follows the clues, he gets closer to uncovering the killer’s identity. But then he realizes—the killer has been watching his stream. And his broadcast is about to take a turn no one expected…