The film opens with a fish tale narrated by a low-class metalsmith in a tavern in Joseon-era south-western Korea. The scene then cuts to a street circus, in which an elegant masked swordmaster (Gang Dong-won) fascinates his market-place audience. Undercover detective Ahn (Ahn Sung-ki), and his protégé Namsoon (Ha Ji-won) are tracking down suspected money-counterfeiter gang, when the masked swordmaster ends his show by killing a government official who carries the kingdom's currency metal cast.