Sergeant Tong is wracked with guilt after he unwittingly kills a young girl whilst capuring a criminal named Cheung. When the girl's sister is later kidnapped in a ploy to get Cheung released, Sergeant Tong vows to find and rescue her before she comes to harm.

By a strange twist of fate, dutiful Hong Kong policeman Dan saves the life of the leader of a violent gang of armed robbers. When they commit another crime, Dan is determined to put an end to their activities. He works with the leader, whom the gang had betrayed, to engineer a plan to wreak havoc within the gang and let the gangsters kill one another. But it becomes increasingly obvious to Dan and to his colleagues that Dan is suffering from a severe mental disorder, and Dan finds that instead of upholding the law as a righteous police officer, he has now become a fugitive wanted for murder.

An absentee father and his bipolar son are forced to live together as they struggle with a recent family tragedy. The tension and anxiety boil as they live and try to cope in a tiny apartment. As time passes, they realize their shared pain is not their only source of grief, as they find the outside world is a cruel and unjust place.