The story opens with a description of a young detective who solves murder cases and is forced to take a potion to transform himself into an old man. The potion is so powerful that he is able to solve even murder cases as a young boy. The young detective takes the potion and sells it to a girl who has been longing to live in the big city. The girl is shocked to find that the potion is only selling for 29.90 yuan. The old man is shocked that the girl is buying the potion for such a low price. He tells the girl that she looks just like her dead boyfriend. She tells him that her boyfriend was the lead singer in a Broadway show and that she wants to marry him. She asks the old man to show her the fallen angel that cost 200 yuan when he was alive. The man tells her that she is charming and that her father gave her the potion