
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 and the guys buy a time machine prop from a classic movie; Penny tells the guys their obsession with comics and toys is pathetic.
Leonard devises a plan to eliminate his rivals when he, Wolowitz and Koothrappali all fall for Sheldon's twin sister, but his plan backfires when Sheldon decides to choose who his sister dates.
Penny learns that Leonard does not celebrate birthdays, so she plans a surprise party; Sheldon unexpectedly gets to live out one of his biggest fantasies in an electronics store.
When Leonard finally works up the courage to ask Penny out on a date, they each turn to Sheldon for advice.