Ah Heng is grounded on Jade Mountain and she exchanges letters with Chi You. After 30 years without the possibility to leave the mountain, Ah Heng becomed depressed envying at the same time the freedom of Chi You, so she gradually stopped replying to his letters.
Chi You's letters kept coming, until one day, a letter grabbed her attention. One line appeared normal but pierced her eyes: "Passing the small hills, the peach blossom flowers ablaze, burning over both shores, a girl starching clothes by the river, I though of you again.." The unintentional "again" caused Xi Leng to turn in her sleep for one whole night.
From the simple sentence "I though of you again", I can immediately feel how much Chi You loves her making also Ah Heng realize how often Chi You thinks about her, it's really beautifully written.