Plot.

Choi Moon Bok is the Devil Rider, a messenger that's so fast that no enemy can catch him as he rides through their camps. During the years of the Manchu War, lords of the court gather to try and call upon scattered soldiers to mount a counterattack against the Manchu army. In order to do this they need a messenger that can ride fast and escape enemy hands. The Devil Rider is just the man but his wife is due to give birth on the night of his departure. He sacrifices being there with her to do his duty for his country. He manages to ride through the enemy, but it's all in vain. His wife dies in labor and the king has already signed peace negotiations with the Manchus. This story takes place 14 years after these events as a cunning and powerful woman named Seoyeon tries to enact revenge for her father's death. She needs the Devil Rider to carry out.