Well made, but after 10 episodes or so we know everything that's truly important... The last episodes were much less interesting than the first, and so it falls a bit flat near the end. Still, a solid 8 in my opinion, and a thriller worth watching.

What I really liked was the backstory and the interesting character of Namgoong Min. The background music was also very good and added to the dramatic feel of it all.

What I liked less was the scientific nonsense. It's to be expected in any story that attempts to incorporate sci-fi elements of course, which makes it forgivable as long as it is not too obvious - I could forgive it here because I've seen worse. It definitely paints scientists as people without a conscience though, willing to sacrifice anything for an endgoal. But then, every story needs a bad guy so that too is forgivable. And as opposed to other kdramas, they do make the police upper management not entirely corrupt but more of a grey zone, which is something I haven't seen too often: they're either made out to be the bad or the good guys.

Regarding the storyline. It starts incredibly strong: you're wondering who the culprit is, and then Captain Do is this fascinating mystery. But at a certain point half-way into the story, all of his mysteriousness is gone. We know exactly who he is and how he came to be at this point in his life, why he does what he does. And sadly, as his mystery is gone, so is the plot development and my interest. At that point, the story is just like this. Team Evil tries to get Captain Do, they fail, and Captain do tries to find their location and gradually gets closer but never close enough. The story just doesn't move along anymore.

And so, while it was interesting enough to watch the show completely, it doesn't match up with the best of the best thrillers out there.