Season 3, Episode 1 - The Electric Can Opener Fluctuation
Aired September 21, 2009
After the gang return from their Arctic expedition, Sheldon is stunned to learn that the guys manipulated his data and invalidated his research. Fearing his scientific reputation has been ruined, Sheldon retreats to his mother's house in Texas. Meanwhile, Leonard catches up with Penny after his summer away, but just as it seems like a relationship is about to start, Leonard must fly to Texas to bring Sheldon home.