This article contains character information for the television show NUMB3RS. The focus of the show is the relationship between brothers Don and Charlie Eppes. Don is an FBI agent, and Charlie is a mathematics professor who consults with Don's team. The show's regular and recurring cast of characters consists primarily of FBI personnel and the faculty and students of Charlie's fictitious workplace, the California Institute of Science (CalSci), and also includes Don and Charlie's father, retired urban planner Alan Eppes.