And when Eric says "technothriller", he means technothriller. There was the obligatory romance between the male and female leads, murder attempts on the protagonists, a plot-critical break-in to a secured installation, and a denouement with lots of explosions. Lay your hands on a copy and find out how this is all true!
The production values were excellent. I can't speak to the correctness of the historical dressing (I know little about Korean medieval costume) but it all looked consistent and period-appropriate. The soundtrack was good too, though surprisingly it was all Western!