Several characters from previous seasons did not appear in season 4, most notably Mildred Finch and Ian Edgerton.
Season five opens three weeks after "When Worlds Collide" (season four's season finale), with the government dropping the charges against Charlie.
Brothers Ridley and Tony Scott produced Numbers; its production companies are the Scott brothers' Scott Free Productions and CBS Television Studios (originally Paramount Network Television, and later CBS Paramount Network Television).
Amita has troubles adjusting in her new role as a Cal Sci professor, and Larry announces his leave of absence—he will be on the International Space Station for six months, which greatly distresses Charlie. Mildred Finch, the newly appointed Chair of the Cal Sci Physics, Mathematics, and Astronomy Division, whom they learn has begun dating Alan.
For example, in the episode "In Plain Sight" (season 2, episode 8), one of the criminals is named Rolle and Charlie's father mentions a meeting with a man named Robert Peterson. The first season run of the show aired between January 23, 2005, and May 13, 2005, at p.m. It sees the start of the working relationship between Los Angeles' FBI field office and Charlie Eppes.
Opening: (Voice-over by David Krumholtz) We all use math every day. The main FBI agents are Charlie's brother, Don Eppes, and Terry Lake, as well as David Sinclair.
Meanwhile, Don dates Agent Liz Warner and questions his ethics and self-worth, and receives counseling.
Charlie sees Don's therapist and the two understand one another more.