In a time when demons rule over cultivators and ordinary people, the elder cultivators decide they need to send someone back in time to learn how to stop the demon lord from coming back to life.

Li Su Su takes on this important mission, assuming the identity of mortal Ye Xi Wu, the second daughter of General Ye. She is married to Tantai Jin, the prince who will become the demon lord and cause great destruction in the future. Li Su Su is determined to stop him, but as she learns about Tantai Jin's past and how he became powerful, she discovers a surprising story that makes her mission much more complicated.