Disturbed

"Disturbed" is the 21st episode of the fifth season of the American television show Numbers. 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. Plot summary A woman is killed in her house in broad daylight. FBI math consultant Dr. Charlie Eppes (David Krumholtz), who has found a temporal pattern in a series of unrelated murders, tells skeptical FBI Special Agents David Sinclair (Alimi Ballard) and Colby Granger (Dylan Bruno) that the murders, including the woman's murder, must be the work of an undetected serial killer with a kill count of almost 70 victims. Charlie's obsession with the serial killer worries David, Colby, and FBI Special Agents Liz Warner (Aya Sumika) and Nikki Betancourt (Sophina Brown), as they suspect that Charlie may be suffering from post-traumatic stress disorder (PTSD). Five days before, Charlie's brother, FBI Special Agent Don Eppes (Rob Morrow), suffered a life-threatening stab wound while investigating a home invasion, and Charlie blamed himself for Don's injury. At Charlie's house, Don, who is there recuperating from his injury, confronts Charlie about his behavior.