Signal (2016)

A decade and a half ago, an innocent girl's journey home from school was abruptly halted by a chilling abduction. The only witness was Park Hae Yeong, a young elementary school student, who watched helplessly as the girl was spirited away. The girl's life was tragically cut short, her body found days later, while the identity of the monster who took her life remained shrouded in mystery. This unresolved injustice planted seeds of mistrust towards the police in Hae Yeong's young heart. Fast forward to fifteen years later, Hae Yeong has transformed his mistrust into motivation, becoming a police officer and an astute criminal profiler. One fateful day, an old walkie-talkie crosses his path, mysteriously bridging the gap between time, connecting him to Detective Lee Jae Han from the past. United by this inexplicable bond, Hae Yeong, Detective Jae Han, and the tenacious Cha So Hyun embark on a relentless quest to unravel unsolved mysteries, venturing down a path where the past and present collide.

Signal is a crime show featuring Lee Je-hoon and created by Kim Eun-hee.

Signal is currently streaming for free (ad-supported) on The Roku Channel and Tubi TV and it's also available on Paramount Plus, Paramount Plus Apple TV Channel and Paramount+ Amazon Channel.