This is the story of Tae-yul, the best swordsman in the Korean Kingdom of Joseon, who serves King Gwanghaegun as his bodyguard. He refuses to join a rebellion to remove the king from power and ends up in self-imposed exile. Years later, he lives in a house on a wooded mountain side with his daughter, who is, by then, a teenager. The story develops from there.
The Kingdom of Joseon lasted for 500 years, from 1392 AD. The story takes place in the 1620s/1640s, when the Kingdom of Joseon had become, in effect, a vassal state of China, i.e. retained a measure of independence but answered (and paid tribute) to the Qing dynasty of China. (The Qing dynasty seized control of Beijing in 1644.) In the film, Joseon suffers at the hands of Gurutai, a ruthless and cruel relative of the Qing emperor. Gurutai has become rich thanks to the slave trade; he started enslaving and selling captives during the recent Qing invasion of Joseon. Gurutai works with the feared Hwangdang slave traders. The authorities of Joseon are afraid to take them on and they, in effect, terrorize the local population. [The Qing dynasty was of Manchu origin, i.e. from Manchuria, and, in the film, reference is also made to the Ming dynasty: this was the purely Han Chinese dynasty that preceded the Qing dynasty. In the movie, the elite of the Kingdom of Joseon is divided between its historical allegiance to the Ming, and submission to the newly arrived Qing, as well as its desire to assert the independence of Joseon.]
The film is well-made in my opinion. Beyond the historical context, which can be confusing if you are not familiar with Korean history, the plot is actually quite simple (I don't want to spoilt it by discussing it), going from period film to action movie, as it were. The fight scenes are excellent and, at times, breath-taking, with that combination of swordsmanship and martial arts that is typical of the Far East. One large-scale fight is clearly implausible in the way that it develops, but the film is enjoyable overall. As far as that kind of movie is concerned and within the parameters of the genre, it is a good film.
Too much of this film is boring palace politicking between Mings and Qings (it’ll help to bone up on Korean history beforehand). Our silent half-blind floppy-haired hero spends half the film living a dull life on a mountainside with his daughter. Given that you’ll be drawn to this film for its action scenes, you’ll have to wait an hour for him to pick up his sword and fully engage with the baddies. It’s ridiculous, of course, but his floppy-haired battle with hordes of baddies, including one lot with rifles, is beautifully choreographed and shot, so much so that the final fight with the chief baddie is something of an anti-climax. Apart from those two fights, the movie has little to offer.