 Wang Shen (Li Nanxing) is smart and has the  no-nonsense  attitude. He likes to keep his emotions to himself. Jiang Dihui (Julian Cheung), smart and mischief, is Wang Shen s total opposite. He laughed and cried whenever he likes. He never kept his emotions to himself. Both are officers of Singapore s Central Narcotics Bureau, who share the goal to take down the mastermind behind drug trafficking. Two best friends were separated when they were assigned to different countries as part of exchange programs. They are colleagues. They are best friends. Will they turn into enemies? As plot thicken, they never dreamed for what had started as a simple exchange programs will turn into their worst nightmares.