It is the story of two friends in a time of political tension who find themselves at aiming their swords against one another due to differences in opinion about their country.
Seo Hwi is a warrior. His life devolves into a hellish existence, but he still holds a smile. Nam Sun Ho is smart and a talented figure. He wants to pass the military service examination. Due to a corruption scandal involving his father, Nam Sun Ho loses his dream. Making things worse, he comes into conflict with Seo Hwi over a misunderstanding.

I entered this drama a bit skeptical, to be honest I like Korean productions above all, especially thrillers, on the other hand, there is one thing that I watch the least, it is historical drama productions because China is really top-notch in this (despite censorship), so I tend to watch theirs rather than others in general.
Now, what attracted me the most in this story was the marketed bromance between the two main characters, I like well-made friendships between male characters. However, I was afraid for a while that the romance would take over, and especially that Han Hee Jae, the female lead, would find herself between the two and give us another badly done version of a love triangle.
And honestly, I'm glad that wasn't the case, not only is the friendship of the two male leads central to the story, but the romance doesn't take up much space, to the point that the writers would even been able to refrain from adding it because it brought nothing.

Now, Han Hee Jae got her role, her back story, her character is midly interesting so I think overall she brought a bit, but hey, not only was the romance not necessary, but she's also one of the only ones characters from the main cast that didn't measure up to the others.

As for our two lead males, I must say that their story is fascinating, despite the misunderstandings, the lies, the half-truths, they really have the kind of incredible friendship. The number of times they fought for each other, protecting each other at the risk of their lives despite swearing the opposite. I think one of the phrases sum up pretty well their relationship, they are like the sun and the moon. The opposite of one and the other, but inseparable despite all the trials.
Really, their friendship was the highlight.

Yang Se Jong is playing Seo Hwi, he's an actor I discovered in the thriller "Duel" and I still remember his superb performance, his role here was really emotional and versatile, he showed so many layers to his character that I'm really glad he got that role.

As for Woo Do Hwan, who plays the role of Nam Sun Ho, I saw him in "The King : Eternal Monarch" which to me was such a waste of his potential, he is made for lead roles and complex characters, like here. I believe he was the most complex character of all, he also sacrificed a lot, being in the shadows to support and save Seo Hwi time after time.

For the rest of the cast, I'm happy to see Jang Hyuk as Prince Yi Bang Won again, I discovered him in "Voice" in a superb role of sensitivity but his role in "Tell Me What You Saw" left me disappointed, I'm really happy to have rediscovered him here because he's a good actor. The rest of the actors did a good job, we hated those who should be and appreciate those who should too. I really got attached to some of them.

Now, for the production, I was afraid to end up with the kind of light-hearted drama like "Hwarang" which honestly makes me dislike Korean historical dramas. Such was my surprise to see that it was very well shot, the tones are correct for this kind of intense drama. The fight scenes are very well choreographed, the sets are superb and the costumes are really beautiful.

As for the script, I must say that it was a bit long, yet each episode was at most 1 hour 20 minutes long, and with sixteen of them. I think I would have liked the plot to evolve more quickly or add more meaningful scenes, or have some removed, and I understand that emotionally we follow the journey of the characters and how they got to a certain point, but it's slow sometimes. But I liked the political plots, although they weren't that much impressive and developped, it was entertaining to keep the tension going. I've seen people say it was the best historical drama of 2019, I seem a correct assumption for Korean ones.
However, one thing that bothered me was that the injuries didn't make sense. The number of times the male leads got pierced by swords and should have died, only to find themselves running ten minutes later and fighting, while Seo Hwi's sister, Seo Yeon, she is also pierced but she dies and so many other characters too. It's just annoying that the realism was not extended on this aspect while they did a good job with the rest overall.

The end was good, I like that it's somehow a happy one, and a sad one. I think our characters had endured so much that they were "exhausted" with life, especially Nam Sun Ho, the ending just feels right and realistic.

So, I recommend for sure, it's really a series to see and re-see, the OST also especially "River Flower" was the best to me. It's really character-driven, with a solid overall story that helps support this incredible cast, the friendship of the two leads was the highlight, especially to show that love in a friendship is sometimes just enough and stronger than anything.