Langston and the team investigate the brutal murder of a family, eventually tracing the killer to the house next door where they discover a machine shop where specialized medical tools are being constructed leading them to believe that they may have stumbled upon the home of Dr. Jekyll. They soon trace the missing homeowner to his mother’s house, where he is found crazed and raving, having killed his mother. The man dies suddenly, however, when Langston and Robbins examine him, they discover a small radioactive pellet embedded in the man’s brain. They surmise that this pellet is what caused his killing spree and death and realize that the dead man was actually helping Dr. Jekyll create his specialized surgical instruments. Dr. Jekyll killed him as well, effectively eliminating the one person who could identify him.