In a way, this drama reminds of Signal, but only with the time travel part. Otherwise, it is another fascinating drama by OCN based on the Hwaseong Murders. To give a little background, the Hwaseong Murders is a famous case that was never solved in S. Korea. Several women ranging from ages 14- 70 were strangled by their own clothing by a serial killer. Tunnel features a homicide detective in the 1980s who is in the middle of investigating a series of murders where the victim is strangled by her own pantyhose and the ankles are dotted in the order they were killed. After several false leads, detective Gwang-Ho manages to catch a glimpse of a mysterious man in a tunnel. While running after said man, he is knocked out on the head with a rock by the man. When he wake up and tries to get out of the tunnel, he ends up walking into another world. This world is the same as his, but 30 years in the future. He is extremely confused as to what is going on and tries to make sense of it by going to his police station. He pretends to be an officer with the same name, but his experience gives him away. Coincidentally, a junior officer of his has now become chief at the same station. His junior officer recognizes his friend that had disappeared 30 years ago. In the past, his body is never found and his team is disbanded after the tragic event. Together, in the future, they try to make sense of what has happened, where Gwang-Ho’s wife is, and how to get back to his time. Of course, adapting to the new traditions at the police station is difficult. He ends up clashing with Sun Jae, an extremely smart detective who is also quite abrasive. Joining the bunch is Jae-Yi, a criminal psychologist who lends her expertise to the homicide unit.
I absolutely love special units that focus on certain types of crimes. Mix in time travel like Signal, this drama is right up my alley. Gwang-Ho played by Jin-Hyuk is perfect in the way that he can be both gritty as well as clean cut. He keeps all his surprise at the future world in his head and I am surprised no one else is more suspicious of his apparent lack of knowledge of current technology. Sun Jae is usual prickly cop who is more than competent, but has a chip on his shoulder. I am hoping that there will be a bromance soon between Sun Jae and Gwang-Ho as they begin to trust each other more. Now the most interesting for me is actually Jae Yi. She is so interesting, but also so creepy. Her expressionless face and abrupt way of communicating with others is fascinating. She seems so absorbed into the psyches of murderers that I am wondering if that will affect her current psyche itself. These three experts make an excellent team if only they can start trusting and working together more. I am so excited to see how this drama will turn out as OCN has never disappointed me!