Xin encountered a car accident while riding a bus. In the darkness, she was rescued by a man Yong. It turned out that Yong thought she was his girlfriend and dragged her out of the car. However, his own girlfriend was not rescued and died due to a car explosion. Because his girlfriend was pregnant, one was killed and two were killed. Yong lost his lover and child at the same time.
In order to repay Yong's life-saving grace, Xin accepted Yong's pursuit and lived with Yong. Later, Yong discovered that Xin was an unmarried mother with a four-year-old son.
Faced with Yong's questioning, Xin began to tell her unfortunate experience: One day five years ago, Xin, who was in high school, collapsed due to a heart attack on the way to school.