Park Seonghwa, the Emperor's right hand man and elite assassin had been for years climbing to the top to serve the king in an attempt to earn enough money to help support his family who, through generations, had been terribly poor and barely managed to scrape by. He never questioned any of the missions given to him until one day, he was given the task to assassinate the head of the Donghak Peasant Movement, a rebel group that was a direct threat to the Joseon Dynasty, but murdering this individual is much harder than it seems.

Nearly every pirate had heard of the Lady Twilight, a ship that had wrecked on a mysterious island nearly eighty years ago that was rumored to contain millions of jewels and hundreds of pounds of gold, and almost every pirate had made it their mission in life to find that ship. Of course, Captain Hongjoong and his crew also sought after the wreck of the Lady Twilight. They had been searching for years and years, until one day, they made a startling discovery that lead them straight to the Lady Twilight. The island, however, may have a bit more to it than it seems.

When mental institution nurse Young Hyejin suddenly disappears and convicted serial killer Choi San, a patient on the ward Hyejin works in goes missing, it is up to Hyejin's co-worker and close friend Park Seonghwa to save her, but things are much worse than it seems...