 Jiang Yiju (Bobby Au Yeung) comes from a long line of card sharps and confidence men, however rather than using the skills he has learnt for crime, Jiang Yiju is instead a policeman of the Hong Kong Police Force who, together with a small squad of officers, uses his understanding of confidence tricks and tricksters to catch them.His choice of career however sees him come into conflict with members of his extended family dismayed to see their own tricks used against themselves.Chen Weichen (Monica Chan) is Jiang Yiju's fiancée, wishing to put off marriage, Jiang has a long-standing bet with Chen, that if she can beat him at mahjong she can name the day of their marriage, with the knowledge that with his skills at the game that it would be impossible for her to do so without him throwing the game.