The shootings at a wedding banquet lift the curtain on two mysterious cases. Elites from the forensic and police departments work together once again to fight crime and uphold the law. Jack "Pro Sir" Po is a senior chemist who has earned the title of human encyclopedia due to his extensive knowledge. Senior forensic pathologist Chung Hok Sum is dedicated to her work and having studied various courses, she often brings about unexpected results. Pro Sir and Chung Hok Sum become friends due to their work as they fight side by side.
