There is a reason why so many watchers of Watcher enthusiastically endorse it as worth the watch.

(If the repetitiveness in this first sentence grated on your nerves, it’s by design: it foreshadows being subjected over and over again to the same tricks of the storytelling trade, even when not absolutely necessary.)

The most frequently used techniques you will encounter in this show: swift turns in loyalties and alliances, constant use of the moral grayscale, motivations and character traits that invert from clear-cut to murky. It's compelling. Could become tiresome, when done solely for the sake of maintaining viewer interest.

One major plus of this show is that the writer has a good grasp of where the story is going. Minimal meandering, plot holes, fillers. A blessing in K-drama world. Each episode is tightly written, and advances the plot coherently. It’s an example of very good writing. What keeps it from being great is the decision to focus more on the twists and turns in unlocking the secret rather than the inner workings of the characters. The way the puzzle is revealed is too convoluted for its essential simplicity. At its core, the show is a study of the blurred lines between good and evil, of how easy it is to fall from the grace of justice into the damnation of crime. It makes more sense to build it as a psychological rather than a mystery thriller.

By design, the characters are formulaic: The Ambiguous Key Figure, The Stonefaced Bitch, The Bitter-Yet-Idealistic Youngster. The actors are wonderful in fleshing them out and giving them depth.

Han Suk Kyu as Do Chi Gwang maintains the character’s mystique to the end while inspiring in the viewer a deep desire to not end up resenting him.

Seo Kang Joon has a string of strong performances under his belt, and he doesn’t disappoint as Kim Young Koon. In the final stretch of the show it is immensely satisfying to see his character display serious fighting skills, and practically demolish a swarm of attackers.

Kim Hyun Joo deserves serious praise for her turn as Han Tae Joo. It seems to be a trend in K-drama world that strong and competent female characters have an inexplicable drive for acting underhanded, unfeeling and cruel. It is a great compliment to the actress that she manages to avoid turning her into the focus of the viewers’ hatred.

As a catalyst for the majority of the sharp veers in the narrative, Han Tae Joo deserves to be mentioned in more detail. Her moral standing and motivations are the least understandable: she wants revenge so passionately as to be a serial sell-out, yet she backs off from pursuing it to the root cause; when threatened with torture, she chooses herself over her husband, yet years later in the same situation is selfless on behalf of a person who is external to her life; she flip-flops so many times that “when is Tae Joo going to turn and bite you” becomes something of a drinking game. Essentially, her character is the sacrificial offering at the altar of the plot: her decisions provide the twists and turns to the story, while psychological consistency becomes less and less discernible as the show progresses. A fail for the writer, an achievement for the actress.

For those familiar with the relationship between the term “watcher” and biblical angels: if you wonder whether the show’s title references this connection, the answer is – yes. The Watchers—observers and sometimes helpers of mankind—are evoked as both holy, like in the Book of Daniel or either holy or fallen, like in the Book of Enoch. Some watcher-like characters start with pure intentions to bring forth justice, and end up ushering in even more violence and cruelty as they fall into crime. Sometimes, as the reveals pile up, their brutality is so seemingly random and exaggerated that it hurts the logic of the narrative.

The “angels and demons” leitmotif is obvious and becomes explicit in the finale. It is stated verbally in one character’s newly found mission: to become “a Watcher of the Watcher,” someone to openly keep vigil over a brother in arms who is constantly teeter-tottering on the edge of a metaphorical abyss. It is also stated visually: as The Ambiguous Key Figure is giving an official statement, cinematography gives the answer whether we are looking at someone on the side of good or on the side of evil. The solution is offered through a slow vertical span of the camera, which repositions the way the mascot on the coat of arms projects behind the character, either as horns or as wings, ending on… well, you will have to see. It is enjoyable to watch – the show as a whole, and especially this last vignette.

In short, if you are wondering whether to become a viewer of Watcher: it’s worth the time at least to start.