Based on the Hwangseong serial killer real-life story, this melodrama offers a whole investigation journey with suspense and thrill. Many people compare Signal with Tunnel since it based on the same incident. However, Signal is not only based on the Hwaseong case. It has some reference of other SK cold cases. I must say both dramas are a masterpiece with something different to offer. Signal offers you to be inside together with the main character, Lieutenant Park Hae Yong step by step in through the investigation.  It has a more realistic approach and serious tone.

To be honest, this drama makes me miserable so many times. I find the police here were corrupt and uncooperative at all, which make investigation harder and annoying.  There are times where I want to pull my hair because of the chief.  In addition, the drama has a kind of slow pace of the investigation ( which make sense, they investigate cold cases and was given many hurdles by other police too).

Overall it is an amazing crime drama. The main character is logical and has a high analytic skill.