The night in Changzhou City is gentle and beautiful, quiet like a shy girl. It's very late. At this time, in an ordinary residential building, Zhang Lu never fell asleep. This is not because she doesn't want to sleep, but because the current situation makes her unable to fall asleep in the mother's room separated by a wall. From time to time, mother Peng Lan's suppressed moans came from time to time. It is this moan that deliberately lowered in order not to let her daughter hear it. In this quiet night, it seems particularly seductive as if the mirror-like lake surface, waves of ripples dissipate everywhere, making people unable to help but explore the center of the ripples. Sometimes the magic of the sound is far greater than the picture. The moans make people's blood swell and make people think.