Tunnel

In the town of Hwayang, series of murders that took young women's lives away is making everyone feel anxious. Serious Crimes Unit of Hwayang Police Station works day and night to catch the culprit behind the incidents, but for months, they make no progress. At last, Kwang Ho makes a breakthrough and tracks down the murderer behind the murders.

Detective Park Kwang Ho is shocked to find himself transported 30 years forward in time to December 2016, where he assumes the identity of another police officer bearing his name and starts working on a case with a new partner.

Detective Park Kwang Ho, after realizing that he's unable to go back to 1986, is convinced he was sent to the future to solve the 30-year-old serial murder case, but clashes with his coworkers over a new unidentified victim.