Bill Nye "The Science Guy", who is a fan of the show, guest stars as a colleague of scientists Dr. Charlie Eppes (David Krumholtz) and Dr. Larry Fleinhardt (Peter MacNicol).
Arsonists set two fires to a car dealership, one which destroys an SUV and one which kills a salesman.
FBI Special Agents Don Eppes (Rob Morrow), David Sinclair (Alimi Ballard), and Colby Granger (Dylan Bruno), as well as Dr. Charlie Eppes (David Krumholtz) (Don's brother and an FBI math consultant), arrive at the scene and learn that an ecoterrorist group is implicated in the arsons.
When Colby and FBI Special Agent Megan Reeves (Diane Farr) question the ecoterrorist group's members, the group denies involvement in the arsons and accuses the FBI of making false accusations.
When no reaction occurs, Charlie, Larry, and Bill realize that the fire was intentionally set.
Charlie determines that someone tampered with the office building's standpipe to create a lack of water pressure.
Charlie's analysis of the fires confirms the location and reveals that Stevens was behind all of the related arsons, including the fatal one at the car dealership.
In the commentary for "Scorched", Crouch admitted that the most difficult part of writing the script was keeping the plot twist hidden from the audience.
[1] The events of this episode bear some resemblance to the case of William Cottrell, a former Ph.D. candidate at Caltech who was convicted in April 2005 of conspiracy to arson of 8 sport utility vehicles and a Hummer dealership in the name of the Earth Liberation Front.
Incidentally, all of the flames ignited during takes instead of being edited in later, an event that rarely happens in television production.
Barba and the crew also spent a day filming at a construction site in the Simi Valley.
Barba and the crew also built the set serving as the Eppes family's bathroom especially for the episode.
[1] According to series creators Cheryl Heuton and Nicolas Falacci, Bill Nye served as an inspiration for both Numb3rs and for the character of Dr. Charlie Eppes.
[5][6] During season five, she was cast as series regular FBI Special Agent Nikki Betancourt.