position at Harvard University, but is plagued by doubt as her relationship with Charlie is challenged, and her career is in upheaval. Alan begins work and dating again, although he struggles with the loss of his wife and Charlie and his dream of her. Season 3 (2006–07) Numb3rs was renewed for a third season, which began airing at 10:00 pm on Friday, September 22, 2006, and ended on May 18, 2007. Charlie and Amita intensify their relationship, as do Larry and Megan, especially after Megan's kidnapping. Amita has trouble adjusting to her new role as a CalSci professor, and Larry announces his leave of absence; he will be on the International Space Station for six months, which greatly distresses Charlie. Charlie and his colleagues are troubled by Dr. Mildred Finch, the newly appointed chair of the CalSci Physics, Mathematics, and Astronomy Division, whom they learn has begun dating Alan. 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. Despite Don's concerns, Alan engages in some FBI consulting with his engineering knowledge, and Larry returns from the space station, disillusioned. The finale wraps up with a revelation that Colby was a double agent for the Chinese. Noticeable changes from previous seasons include removing the opening-credit sequence (credits are now done during the first segment of the show), the absence of Peter MacNicol's character for much of the season, and the absence of Diane Farr's character for a few episodes. Peter MacNicol appeared in the first 11 episodes before leaving for the television show 24, but returned to Numbers for the 21st episode of season three ("The Art of Reckoning"). His character's absence was written into the show by becoming a payload specialist on the International Space Station. Diane Farr, pregnant for most of the season, left the show for maternity leave in episode 18 ("Democracy"); her character's absence is explained as a particular assignment to the Department of Justice. Season 4 (2007–08) The season premiere aired on September 28, 2007, in the same time slot as in previous seasons, 10:00 pm Eastern Time. Because of the writer's strike, only 12 episodes were initially produced. However, once the strike ended, CBS announced the show's return April 4, 2008, with six episodes. The season ended on May 16, 2008. As this season starts, Colby Granger