I found the earlier parts to be quite good with a reasonable pace. However, 25 episodes later things started to change in a weird direction and the initial spark faded away. Yet, the reality was a letdown. Jeong Do Jeon, the pivotal figure, felt like a distant acquaintance rather than someone I could understand. His struggles and triumphs failed to resonate the longer the drama kept going, leaving me disconnected from the heart of the story by the end of the drama. The ending was very typical with these kind of shows, everyone lose their marbles abruptly so they can jump to the historical ending, if there's any. Jo Jae Hyun and Yoo Dong Geun did a great job as leads, they simply carried the drama with their performance. Even their character was methodical and well written. One thing I wanted to see is having Do Jun's wife playing a bigger role in supporting her husband. I really appreciate their casting choices. Going for a mature looking cast was the correct choice. New to semi-new generation cast with soft looks in their mid 30s would have been disastrous.