Heung Yat Jeen was saved by a kind-hearted man when he was young and since then, his life ambition was to become the world’s best detective. His training and hard work paid off when he solved a mystery case on his first day of work. However, his superior, Ching Ying Hung, was envious of Yat Jeen’s glory and purposely sent him on a dangerous mission to capture a mass murderer, Yi TeenBong. Along the way, Yat Jeen encounters Foon Hei who saves him numerous times. However, being on opposing sides, Yat Jeen begins to have dreams of himself as Zhu Ying Tai from the Butterfly Lovers legend. He continues to believe that his fate with Foon Hei is the reincarnation of the legend and that they are destined to be ill-fated lovers. With the sudden appearance of the daughter of a wealthy merchant, Wu Deep, Yat Jeen’s wild imagination and delusions of the Butterfly Lovers legend spins out of control.