Signal (2016 - 2016)

"Signal" is a detective series about the joint investigation of police officers living in different time periods. Young profiler Park Hae Young unexpectedly discovers a radio through which an unfamiliar male voice calls him by name. It turns out to be the seasoned operative Lee Jae Han, transmitting a message about brutal serial killings in the 1980s. The heroes join forces to catch the dangerous maniac and prevent the emergence of new victims.