Gu Yunting, a man struggling with the presumed death of his wife, Song Qingluo, in a mission in 1978. He is so distraught that he attempts suicide three times, by poisoning, jumping into a river, and cutting his wrists. Meanwhile, Song Qingluo, who is not dead, is posing as her twin sister, Song Chuyue, and is living with Song Chuyue's husband, Meng Ruochen. She does this to protect Meng Ruochen from the grief of losing his wife, fulfilling a deathbed wish from Song Chuyue to care for her husband.