
Mensa-fied best friends and roommates Leonard and Sheldon, physicists who work at the California Institute of Technology, may be able to tell everybody more than they want to know about quantum physics, but getting through most basic social situations, especially ones involving women, totally baffles them. How lucky, then, that babe-alicious waitress/aspiring actress Penny moves in next door. Frequently seen hanging out with Leonard and Sheldon are friends and fellow Caltech scientists Wolowitz and Koothrappali. Will worlds collide? Does Einstein theorize in the woods?

Leonard is horrified when his mother (Christine Baranski) visits.

Cut off from his father's fortune, Koothrappali appoints Sheldon to help him get out of debt; Penny considers joining Leonard at Comic-Con.

Leonard and Penny offer Sheldon's old room to Raj after he moves out of his apartment.

Bernadette runs into her ex-boyfriend (Rick Fox) while attending a science event with Wolowitz.