Is it a simple revenge story? No, it is journey of people insearch of the truth. This story give u two options: will u leave the past and move on OR hold on to it because the truth has not yet been told. As u hear the characters' reason for their choice, u will be standing in the middle of the road unsure if it was you, what will be ur choice? The story itself started in 1984 with the Chimera case which shocked the nation and 35 years later, someone came back killing peeple with the same MO. Upon this, u start seeing characters getting fidgety about the case because it was too similar to the 1984 case. Now u as the audience start to ponder, did somethig wrong happen in 1984? Cha Jae wan, Eugene Hathaway, Lee Joong Yeop and lastly Kim Hyo Kyung come together, each with their own sets of skills, strengths and connections to the Chimera case to search the truth about both the 1984 and 2019 case. Twists, plots and secrets are slowly unveiled and each one more suprising than the other as the story progressed. I have a lot of experience with serial killing series but I did not see this coming. As the truth are revealed and the perpetrator exposed, the latter said ' if only one of them had said the truth, I would have stopped there itself. That's why it is not just not a revenge story but instead the only thing that was asked is ' TRUTH'. A desperate need for the truth turned a person into a monster. It is up to u to decide, was it best to leave the past in the past? One thing I most enjoyed through the show was the depiction of Hate turned to Bromance btw CJW and LJY. It was a marvelous turnover and the depiction of loyalty and trust that ensures btw these 2 characters is a worth-watch.