
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?

Sheldon goes to Las Vegas to win money for science; Penny and Bernadette take Amy wedding dress shopping, but her terrible choice entangles them in a web of lies.

Sheldon and the gang are confused when a young grad student is attracted to him.

Life gets complicated when Stuart starts bringing his new girlfriend home; Penny and Leonard talk about starting a family; Koothrappali explores an arranged marriage.

When Sheldon won't tell anyone why he's never mentioned Tam, his childhood best friend, Leonard takes matters into his own hands; Bernadette and Penny take Raj's fiancée out to dinner to get to know her.