πI recommend a book to you. It's called "The Body of Calamity." Nie Xiaoqiong, the female protagonist of this novel, accidentally walked into an ancient cave while walking in the mountains and was buried inside. In order to survive, she and her " silly son " had tried all kinds of methods, and a strange relationship had occurred between them. Therefore, it meets the requirements of the plot you provided. I hope you like my recommendation.π