Witness Protection Unit (WPU) inspector HUI WAI KIT (Bosco Wong) was ordered to protect the city's wealthy businessman KUI KWONG SAN's (Paul Chun) daughter KUI CHI LAM (Linda Chung), unfolding their destiny! LAM has an isolated and strange personality, where she's trapped in her own world. When KIT comes into her life, she started opening up and developed feelings for KIT. She didn't care about her father's opposition and took the initiative to pursue him! When SAN saw his daughter more outgoing and taking initiative, he started changing his views. However, a 30 some year enemy LAI SUE FUNG (Joesph Lee) suddenly comes back and drove everyone nuts. KIT discovers a secret between FUNG and the KIU brothers, which left KIT in a dilemma as he struggles to find a balance between justice and love.