
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's idea for a smartphone application causes friction in his friendship with Sheldon.

Leonard keeps an affair a secret from Sheldon, Howard and Raj.

Sheldon's interview with the FBI jeopardizes Wolowitz's security clearance.

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