History and culture docent YIU TUNG-NEI keeps having the same dream for over a hundred times. One day, she meets CHO-AN while leading the guided tour and CHO-AN puts a memory card in her handbag secretly. TUNG-NEI discovers an old receipt from a 2nd hand store back in 1997. She asks her father YIU HOK-YAN, a history professor, about the receipt but she gets no answer. TUNG-NEI goes to the address in the receipt and she meets CHO-AN again. Thereafter, somebody abducts her to Brother FU’s Japanese restaurant. After settling the matter, CHO-AN promises to give her free detective service as compensation. CHO-AN helps TUNG-NEI to find the name of the 2nd hand store as well as the old staff Uncle SHING. He believes that his job is done but TUNG-NEI asks him to carry on with the investigation……