I liked the plot and how there were various cases the royal secret agent had to investigate. Also, Joseon dramas are always just so beautiful to look at with the locations and costumes. But as it's happened with pretty much every single Joseon drama I've ever watched, the whole thing was brought down by the villains. I always hate the villain's plots in these kinds of dramas, They're always predictable. For once I'd like to be surprised, for the villain not to be revealed until a breaking point in the story.

Also, the B-plot with the relationship between Yi Gyum's little brother and his ex girlfriend was so unnecessary. The actress they cast had one single facial expression and her delivery was so dry and unemotional. She was a pointless character that the story could have done without.

Other than that, the drama was fine. The three main characters had great chemistry and banter and I really liked Da In's character and story. Not much romance to this one, though.