I only watched this movie because of Kang Dong Won, and boy was I NOT disappointed. Although this is a 'spy thriller' type movie, it also has some laugh-out-loud comedic moments for Song Kang Ho's character, and for the pair together. This movie really is about both friendship and brotherhood. I am no expert on North-South relations, so I don't know how realistic it has been portrayed through the events in this movie, but I think it has been set up very well to show how both characters dealt with the conflicting loyalties they felt to friend and country. The pacing of the movie is done very, very well. We are thrown right smack in the early stages of an operation, which escalates quickly. This quickly drew me into the movie and left me hungry to know what would happen next. The next part of the movie afterwards was slower in pace but was full of both funny and exciting moments, and left me emotionally invested in the friendship between the two main characters, followed by the last third of the movie where the pace picked up and left me on the edge of the seat. The ending was well-written. I am surprised that I have not heard more buzz about this movie. This is a must-watch!