A movie name, her sister is a photographer, and one day she caught a married man and a married woman having an affair.

The film tells the story of two sisters: Ruxing (Zhu Zhiying) and Ruyi (Zhang Junning) live on the upper and lower floors of an apartment. Sister Ruxing is a novelist and sister Ruyi is a photographer. Driven by curiosity, the photographer's sister accidentally photographed a couple having sex naked in the apartment opposite, while the writer's sister was in a state of exhaustion of inspiration. The two sisters began to track down the couple, only to find that the whole thing was not as simple as they thought, and eventually they might even be involved in the murder. ...