Plot Summary:In Hong Kong of 1969, three detectives: Director, Fugu, and Sam live a normal life. They work, eat, sleep, and live in their huge office/apartment on the second floor of an office building. They normally go out to fight crime. One case, however, changed their lives greatly. Fugu brings home a magic lamp and some other broken antiques after a tussle with two thieves at an antique shop. Thinking the lamp will grant him some wishes, he rubs it and wishes to marry his cousin, Jane. He later leaves for the US. Right after he leaves, a friendly witch named Harmy BoBo comes out of the lamp and tries to grant Sam and the Director the wishes. Only Fugu, however, can have the wishes since he rubbed the lamp first. BoBo does not know Fugu left the country, and Sam and Director does not know BoBo is a witch. BoBo decides to spend a few nights with the two detectives. She later gets robbed by the Lotus Seed Gang and leaves her twin cousins (who are originally chopsticks) behind. The twin cousins soon become part of the gang. Trouble begins at this point. While BoBo tries to stop her cousins' criminal acts, the two detectives fight the gang. It's not long when Fugu returns and BoBo's reptilian boyfriend arrives. Then, more adventures follow.
阿文（刘青云 饰）是一名私家侦探，常常压榨他的两名伙计阿杰（古天乐 饰）与鸡泡（陈小春 饰）。他们从古董店里拿回了一只神灯，阿文随手把灯丢到大街上，一个名叫哈咪波波（张栢芝 饰）的女巫从灯里冒出。波波来到了阿文的侦探社，波波要他们每人说出一个愿望，实现后波波才能回到自己的世界，阿杰阿文都以为她是鸡泡的表妹。可是法术失灵，阿文他们都不相信她，她只好一直从中帮助阿文他们几个。阿文的牌局让波波的失灵法术给搅和了，并与石坚（吴镇宇 饰）结仇，石坚也认了波波的筷子姐妹花（Twins 饰）表妹做干女儿。笑话因此不断闹出。
