Tian San Qi (Esther Yu), a curious child who always asked questions, formed a close bond with a boy who disappeared mysteriously, leaving her heartbroken. Years later, San Qi becomes a forensic doctor, dedicating her life to finding her lost friend. With a group of skilled companions, she begins investigating a series of interconnected cases that might reveal clues about her friend's disappearance. As they uncover a decade-long conspiracy, San Qi hopes to finally solve the mystery of the boy who vanished from her life. This is a 2020 Chinese romance drama adapted from the novel "Jin Xin Ji" by Han Xue Fei, directed by Zhou Tong and Dai Meng Ying.