Tian, the son of a high profile officer, receives an emergency heart transplant surgery. When his donor's identity is concealed from him, he's driven to great lengths to discover her identity and manages to recover a notebook that might otherwise have been forgotten. Torfun was a volunteer teacher who died in a traffic collision. From her journal, Tian learns about her life in Phu Phan Dao, a village on the country's northern border. Something about her notebook inspires Tian to take up Torfun's position at the school himself.