The original plot had a lot of potential, but they didn't know how to keep the episodes interesting and interesting. I was sick of everything at first, but thankfully the acting was good, and I really enjoyed their friendship and romance development. Further, the detectives were so stupid when investigating the Ghost case, and the Subway police were doing everything but their job, that it could have been better.

And I had no sympathy for the majority of the characters. The main female lead was annoying the majority of the time; she was nice for three seconds. The second female protagonist? Just move on, girl.

Besides that, while the weekly case was not bad, it made NO difference in the main plot. They squandered so many episodes by doing nothing. I even thought that any case would help build the ghost case, but it didn't, which disappointed me greatly. They didn't give any hints about whom the serial killer was during the drama, and then they just brought a bunch of random facts and tried to connect everything together. Did it work? Not particularly well, but never mind.

Oh, and the last episode was exhausting. Many doors remained open, and I believe they were mostly playing us. Another thing that irritated me was the number of plot twists in the final episodes. I mean, did this roller coaster really need to return to the same location? Wasn't very nice, haha.

Finally, the drama could be easily cut down to 12 episodes. Anyway, it's not a bad drama, but the only way I could finish it was to skip everything. I'd give it a solid 5, but because of the actors' performances, I could tolerate it a little longer. Will I watch it again? Never before in my life.