South Korea excels in producing original thrillers. Now, the first episode is always critical - for me - in order to know the tone, the rhythm and the show as a whole. Insider from its first episode was so good.

It tells the story of a judicial trainee named Kim Yo Han. After going undercover for an investigation, Kim Yo Han experiences a crisis, and end up in prison.

Insider really did it for me. And although the premise is deja vu, with a man - smart and good/naive - finds himself in a bad situation where he will suffer because of the richest essentially - in general a secret organization - and that he will become more than what he was in order to survive, a powerful adversary, Insider had this vulnerability which brings a difference to this show.

Yo Han will suffer, a lot, and I'm not talking about two episodes at most but many episodes where he endures low blows, attacks, ruthless manipulations and the loss of loved ones. And I think the series really did show how a person who starts off smart and resourceful, given a harsh environment to survive, can become powerful. I mean, the man endures a lot, jail and without giving too much away, the people who hold the power, are cruel to him.

I think the show brings an interesting angle on the legal and political state of the country, as a character says "A prosecutor could kill a person in broad daylight with the population around, and walk away without problem", here we see that institutions are intertwined with politics, shenanigans are endless, no one trusts each other, everyone threatens each other. The show also highlights how much money can buy you a lot in the world, so much so that you can control a country or government. And above all, that no one is irreplaceable, everyone no matter how high and sure of their usefulness can be thrown away and someone will take their place, which also shows a terrible ambition and this hunger for power that it gives people - in these professions - who are very quick to be vile and without humanity.

To talk about the show, we follow Yo Han's growth for a while, his evolution especially as he goes through all his difficulties and his strategies, we also see that no one can be trusted no matter how friendly they appear, the investigation for the truth advances slowly but surely with each episode, and they end in cliffhanger especially towards the end of the series. Now, I've binge-watched the show from the first episodes to the 14th, and then I had to wait for the last two episodes as they aired. And it was hard, because the suspense is there. Especially since the first episode, from the first scene which showcases a chase with Yo Han then we have to go back a year, so this scene made me question a lot, how will it happen ?
The side characters are brilliant and really versatile with good backstories, I found some familiar faces I've seen in thrillers, it was nice to see them playing other characters. The plot as a hole is really done well, because in the end, we don't know what the main character wants except his revenge, but how far he will go and how far can he ?
The end is ... hopeful for those who enjoyed the series as I have, if there is to be a second season, honestly I wouldn't mind because this series is very addictive.

As for Yo Han, so the actor, Kang Ha Neul, is really brilliant, he manages to show a character who toughens up but remains very human, and who has his vulnerabilities, I love his duality. Frankly, it's very good acting. This series reminded me in certain aspects of "The Veil" on the other hand, Yo Han as the main character with a vengeance, really pulled off the emotional side for me, whereas although Namkoong Min is a very good actor, he was quite robotic and less natural to show the range of his character.
Kang Ha Neul really did a good job, his character shows a lot of realism, I hope to see him again soon in an ambitious thriller series.

So I recommend this series for those who are stingy with thrillers who have investigations, about revenge with interesting and charismatic characters, political plots without being boring, on the other hand, I say it right away, there is no romance, and very few comedic moments - or none - it depends on people's humor.