Zhen Xiaoxiao, a newly graduated social worker, bought an old doll wearing a pink skirt from the second-hand market in order to decorate her rental house. However, this doll seems to be "alive" - it will grow up on its own and even utter sad murmurs of "I miss my mother" late at night.
A yellowed note hidden in a doll's skirt revealed a cold case of a missing child five years ago. When the doll disappeared and the ghost of a five-year-old girl appeared in front of the window, Zhen Xiaoxiao realized that what she had invited home was not just a doll, but also a young soul that could not rest in peace.
In order to let her soul rest in peace and save herself, Zhen Xiaoxiao is determined to find out the truth. But little does she know that the moment she begins her investigation, she also becomes the prey of someone lurking in the shadows of the city. In that seemingly glamorous amusement park, how many sins and tears are buried under the carousel?
