Zhao Ran, a newly graduated female college student, died unexpectedly of a mental illness due to her high school friend Li Yiran, but she failed to stop it in time, so she has been feeling guilty and suffering from insomnia. Lin Zheng, a psychiatrist, determined to become a psychiatrist because his younger brother suffered from mental illness since he was a child, treating illnesses and saving people. Zhao Ran went to Lin Zheng's clinic for treatment due to insomnia. During the hypnotherapy process, Zhao Ran accidentally returned to five years ago. The year before the tragedy occurred, he accidentally discovered that Lin Zheng had become his high school monitor. The two worked together to investigate the real cause of Li Yiran's death and prevent the tragedy from happening. As the investigation deepened, the truth about Li Yiran's death gradually emerged. Zhao Ran and Lin Zheng also discovered each other's unknown pain during the investigation, healed each other, and moved forward hand in hand.
Purpose: mental health, friendship