In a cold, loveless marriage, Li Xiu'ai is watched for months through her window by Luo Shengchun from across the way, and desire and shame ignite in her at once. Her father-in-law catches them, they meet again on the subway, and her body is tested across one boundary after another—the more she runs, the deeper she sinks. Before the bed is even bought, the relationship between watcher and watched has already been rewritten—and it's only just beginning.