Han Tae Joo works for the Seoul Criminal Investigation Department; he has built his career by relying on scientific evidence rather than anything else. He is far too strict when it comes to the rules, and one day, whilst investigating a serial murder case, he has an accident. He wakes up as a Deputy Inspector at a small police station in the winter of 1988. He doesn’t know why, but he finds himself having to cope with the police brutality of that era and realises that he must do something in the past in order to return to his own time.