I truly enjoyed this drama. I finished it in about a week, and each episode left me eager for the next one. This drama is what The Ghost Detective tried and failed to be: an excellent thriller/horror. The tension was never lost, because the threat of Sohn was ever present, even if he himself was not, hounding the protagonists while they searched for a way to destroy him. There were new threats each episode, as Sohn sent various demons after the main leads in order to impede their progress. The plot twists, all except for one (which I shall touch upon), were excellent. The story kept me on my toes.

*spoilers below*

If this drama had one flaw, it is that it tried to be too clever. The big mystery that the protagonists were trying to figure out was who Sohn was possessing. Was it Matthew's brother, Sang Hyun? Was it Father Yang? Was it Hwa Pyung's father or his grandfather? Was it the politician, Park Hong Joo? Was it Hwa Pyung all along? Honestly, the options that I had held out for was either Sang Hyun, Hong Joo, or Hwa Pyung himself. I especially hoped it would be Hwa Pyung, because they kept hinting that Sohn had been hiding inside him all along, biding his time. Which made the final episode rather disappointing, because it turns out...*dramatic pause*...it was the grandfather all along, and Hwa Pyung never was actually possessed. Uh...? Okay?

The final episode was actually a big disappointment after all of the excellence that came before it. It was extremely badly paced, with nearly 20 minutes of the grandfather/Sohn monologuing and ret-conning almost all of what we were led to believe since episode one. Then there was the chase from Hwa Pyung's house to the beach, a distance which should take maybe 40-50 minutes because the beach can clearly be seen from the house, but gauging by the how the sun is high in the sky at the start, and it is full night when they reach the beach, takes more than 6 hours. I liked the last 20 minutes of the episode, but the first 2/3 of the episode was just really, really bad.

If it had been up to me, the last episode would have gone thus:

Hwa Pyung brings his grandfather home from the hospital, and all seems to be well. Then, Hwa Pyung feels the pain in his right eye again, and he realizes that Sohn did not die. Sohn temporarily takes control of Hwa Pyung's body and forces Hwa Pyung to kill his own grandfather. Hwa Pyung regains control and manages to carve the containment symbols into his own skin. Matthew and Gil Young arrive to find him like that. Matthew attempts to exorcise Sohn from Hwa Pyung, but partway through the exorcism, Matthew suffers excruciating pain (due to the curse), and Sohn breaks free and attacks. Gil Young tries to stop him, but Sohn has inhuman strength and knocks her away. Hwa Pyung barely manages to resurface before Sohn kills Matthew, and flees down towards the beach.

From here, the episode plays out the way they wrote it, though, my final complaint is that it would've been nice if they had clarified that Matthew's curse disappeared when Sohn died, rather than just showing that he's fine a year later.