Single mother Xia Tian (played by Yang Mi) is a senior researcher at the Institute of Physics. Together with the director, she has developed a technology that allows organisms to travel through wormholes in time. When the research has made a breakthrough, her son Dou Dou (played by Zhang Yihan) is kidnapped by the mysterious kidnapper Cui Hu (played by Huo Jianhua). In order to save Dou Dou's life, Xia Tian risks using the unfinished particle technology to go back 1 hour and 50 minutes, but things become more complicated and she encounters an unexpected dilemma: she has to face three variations of herself in time travel. Cui Hu's story gradually surfaces...