The CEO of Gu Group, Gu Xiaoran, and the biological mother of his son, Lu Tongtong, are kidnapped and killed by criminals. Doudou witnesses the whole event and cannot accept the death of her parents. She convinces her uncle to use a time machine to send her back to the time before her parents' death in an effort to save them and change the outcome. To successfully complete her mission, Doudou brings a handheld computer and possesses the ability to sense the future. However, Doudou only has one month. If she fails to complete the task, she will disappear, and her parents' tragic fate will repeat. After traveling back in time, Doudou stays close to Lu Tongtong, helping her outsmart the scummy man and woman, while constantly creating opportunities for Lu Tongtong and Gu Xiaoran to meet. Through Doudou's relentless efforts, the identity of the murderer gradually comes to light, and Gu Xiaoran begins to fall in love with Lu Tongtong.
