Genius surgeon Shen Zhao has an unknown identity - the top killer "Yedie". When she meets Pei Yan, an upstart business man, an operation reveals a secret that has been sealed for twenty years. The crescent scar on Pei Yan's body, the butterfly birthmark behind her ear, and the snake-shaped coat of arms of the Night Watch organization, all clues point to the Pei Group's underground laboratory. In a maze of black and white, two highly intelligent souls engage in a life-and-death struggle, but they don't know that they have already fallen into a genetic experiment conspiracy that spans twenty years. When the truth emerges, they discover that each other is just a pawn on the chessboard, and that the real chess player is hidden behind the fog of memory.
