Xia Huai and Jiang Yu, the top students in high school, became happy friends because they were divided into classes. The secret of Xia Huai's congenital heart disease and Jiang Yu's sister's medical accident gradually came to light.
The two discovered that they were involved in a time loop of drug experiments, and the heavy rain became a quantum signal to restart the experiment.
Jiang Nuan's heart and memory were implanted in Xia Huai's body, and Jiang Yu pretended to be his sister to find out the truth.
The underground laboratory reveals Director Li's clone army's conspiracy to control the time cocoon room, and the heavy rain reverses the flow of time and triggers the collapse of time and space.
The two tear apart the boundary between virtuality and reality, and return to the eve of the rainstorm in 2017 at the singularity of time, holding the last chance to reverse the tragedy.
Motto: Accident always comes before luck
