Five hundred years ago, in order to save An An, Bigan gave his exquisite heart with seven orifices to An An. In order to save the careless Bi Gan, the medical god installed a clock heart in Bigan. Bigan therefore became the person who measures and controls time in hell. Traveling in the past, future and present, he accidentally met An An's reincarnation five hundred years ago, Lian Xin, a medical student in medical school determined to become a heart surgery expert. In short, the story is amazing, you can see it is the beginning of the story!