Numb3rs: Disturbed

"Disturbed" is the 21st episode of the fifth season of the American television show Numb3rs. In the episode written by series creators/executive producers Cheryl Heuton and Nicolas Falacci, skeptical Federal Bureau of Investigation (FBI) agents track an undetected serial killer while their math consultant copes with his brother's recent injury. After FBI Special Agent Don Eppes's (Rob Morrow) injury, FBI Special Agent David Sinclair (Alimi Ballard), who was the newest member of the team at the beginning of the series, served as team leader. Falacci and Heuton also included Easter eggs from the "Pilot" and from some of the previous 99 episodes. The producers brought back one previous guest star and almost had a special guest star. For the 100th episode, series producers brought back Josh Gad, who amazed producers in a previous episode. Dr. Stephen Hawking, who visited the set during filming, almost became a guest star in the episode. "Disturbed" first aired in the United States on May 1, 2009. Critics generally liked the episode.