When a Hong Kong celebrity is found brutally murdered, his body floating in the middle of the ocean, hardheaded detective Lam is called in to take charge of the investigation. As Lam zeroes in on a killer from the past, the murder appears to be a straightforward case of revenge. But the more that Lam pursues his suspect, the deeper he falls into a web of lies. To find the truth, Lam must dig into a 20 year-old case for answers, the one link tying the suspect to the celebrity. But in doing so, Lam will uncover a dark secret so shocking; it will turn the investigation upside down. Who is the victim and who is the killer? Just as Lam believes he has everything figured out, he will discover that there's a fine line between love and hate.