Duel is an interesting tale that serves as a commentary on morality, what it means to be human and what one can do for survival. It mixes typical corruption and crime plot lines with underlying science fiction elements. Sadly, the lack of balance in terms of writing the characters and their backgrounds makes it hard to truly enjoy and appreciate it.

To keep it simple, this show kept making me feel angry, depressed and frustrated. This drama was determined to dump any possible bad event on one character, not letting him, nor me as a viewer, take even a small chill break. By the end of the show I couldn't care less about any other character except for Sung Hoon. While making me care so much about the "villain" - the angry, manipulative and selfish one of the Sungs could be considered excellent writing, the fact that it also makes me dislike Sung Joon says otherwise.

How many writing mistakes must you commit to make me dislike the good, loyal, selfless and cute character, while I wish to see the happiness of the evil, shady and selfish one? And that's where the lack of balance shows. The good guy was too good and didn't have an interesting backstory, while the bad guy had a compelling background and more complex personality.

The plot follows a rather typical structure of a crime show. The science fiction aspect has little if not no closure. All storylines for each character got a conclusion - some more, some less satisfying.

I have to applaud Yang Se Jong's performance. He aced both the goodness in Sung Joon and madness in Sung Hoon. Truly believable dual acting. I wasn't the biggest fan of Kim Jung Eun in here, but I'm honestly not sure if the problem was her acting, or how her character was written.

Overall, watch it if you like to suffer and be frustrated - for some people it makes them feel alive. For me, the drama could have dived deeper into how external circumstances can shape who we are and how we act, what it means to act morally and if it even matters when faced with a life or death situation.