Dr. Chester Ray Banton (played by Tony Shalhoub) was a physicist who did groundbreaking research into dark matter. During a key experiment, he entered a chamber and was exposed to intense dark matter radiation that turned his shadow into a killer void that disintegrated any living matter it crossed. Banton went on the run for fear that the government would use his experiments for sinister purposes or imprison him for study and experimentation. Following the disintegration deaths of several people and two police officers, he met Mulder and Scully, in whom he saw safety. Mulder sought assistance from X in dealing with Banton, but X betrayed Mulder's confidence and used knowledge of Banton's whereabouts to find him. Banton attempted to reverse the dark matter exposure by entering the experime