Hui Wai Sam (Bosco Wong) is a Witness Protection Unit (WPU) officer who is very dedicate in his job. Due to a case that involves the potential assassination of wealthy businessman Kiu Kong San’s (Paul Chun) younger brother, Kiu Kong Ho (Ram Tseung), Wai Sam is ordered to protect Kon San’s only daughter and surviving child, Kiu Chi Lam (Linda Chung).
Chi Lam witnessed the person who tried to assassinated her uncle and now her life is on the line.
Chi Lam is a cellist who suffers from depression ever since she witness the death of her very own brother at young age. She holds herself responsible for his death and gradually closed herself off from the rest of the world. Because of this reason, she has very few social ties to the outside world and uses music to isolate herself from others. Chi Lam is locked in her own little world but when Wai Sam comes into her life, he becomes the key to her world. He teaches her the true meaning of happiness and slowly expands her little world from little to huge.
She soon finds herself falling for him and even takes the initiative to pursue him despite her father’s opposition. However, as he sees her daughter becoming more outgoing and happy, he starts to change his views.
Kong San is still unsure of his daughter’s relationship with Wai Sam because of his occupation as a police may threaten to ruin his wealth and status. To complicate matters further, Lai Sue Fung (Joseph Lee), a long time enemy reappears. Thirty years ago, Kong San was involved in some questionable dealings with Sue Fung which lead to his profound wealth.
Wai Sam discovers a secret between Kong San and Sue Fung with could threaten to reveal the Kiu brother’s wealthy past. This leaves him stuck in the middle as he struggles to find the balance between love and justice. What must he do in order to find this balance? Or will he just abandon love for justice?