A small puppet doll holding a royal secret sets off a wave of bloodshed in the Qing Dynasty. Asked by a prince to protect the puppet, lone swordsman Tuen Long (Ekin Cheng) finds himself fending off agents and assassins including Chin Sik (Noel Leung). Chin Sik’s failure to complete her mission tragically leads to the death of her entire family. From that day on, Chin Sik relentlessly pursues Tuen Long for revenge, but as they spend more and more time together, she ends up falling for the man she intended to kill. Torn between the steadfast love of fiery Chin Sik and gentle Chi Lan (Ho Yuen Ying), Tuen Long knows not where his drifting heart and home lies. Matters of the heart take on life-or-death consequences when the dangerous conspiracy behind the puppet doll slowly reveals itself.