Devastated over his girlfriend’s death in a traffic accident, psychologist CHUNG TAI-YIN (Kenneth Ma) has spent five years to seek the truth. The psychological assessment of a campus murder suspect, LO KIN-KEUNG (Willie Wai), conducted by his late girlfriend showed that KIN-KEUNG lacked a murder motive and had no violent tendency. During TAI-YIN’s investigation, he encounters a prodigy named TUNG YAT (Mat Yeung) who has Asperger’s syndrome, and his younger sister TUNG YUET (Sisley Choi). TUNG YAT is socially awkward and often brings trouble to his sister.