In 1969 of Hong Kong, private detective agency director Man (Sean Lau) and his two employees, Sam (Louis Koo) and Fugu (Jordan Chan), are investigating an adultery case, where they track their target and crashing into an antique shop, where they end up causing a lot of damage there. Man, who is greedy and miserly, forces Sam and Fugu to be held responsible for the damages, while Sam pushes all responsibility solely on Fugu. In the pile of debris, Fugu finds a lamp which was unable to turn on. At the same time, Fugu also receives a call from his aunt informing him that her cousin, Jane Lam (Christy Chung), who is a student of Stanford University studying Aerospace Technology, have gone mad due to over-studying, and is now missing. Fugu is worried to ask Man for a leave of absence. Man and Sam both took a look at the lamp, which was still unable to turn on, where Man throws the lamp out the window. At this point a sorceress named Harmy Bobo (portrayed by Cecilia Cheung, the character's name is a parody of Harry Potter) magically emerges from the lamp. Bobo arrives at Man's agency and asks the trio to each make a wish, so she can return to her world. Man and Sam both thinks Bobo is Fugu's cousin. However, as Bobo fails in her spells, the trio do not believe her to be sorceress, but she continues to help them in secret. One time in a mahjong game, Bobo's failed spells causes Man to be exposed from his cheating, and thus, he forges a rivalry with gang boss Kin (Francis Ng). Bobo's cousins, the Chopstick Sisters (Charlene Choi, Gillian Chung), also happen to be at the hands of Kin, who took them as his goddaughters.