Aired Saturday July 24, 4:10pm - 4:40pmon E4 +1

The Big Bang Theory

Series 2 Episode 20: The Hofstadter Isotope

Leonard is devastated when the geeky sales clerk in a comic book store hits on Penny. Even worse, she doesn't mind! Leonard can't believe that Penny would date one of `them', unless it is him. Sheldon tries to scupper the budding romance by constantly challenging the clerk to engage in dialogue from Batman.

Category
Sitcom
Original air date
2009-04-13
Cast and crew
  • Johnny GaleckiLeonard Hofstadter
  • Jim ParsonsSheldon Cooper
  • Kaley CuocoPenny
  • Simon HelbergHoward Wolowitz
  • Kunal NayyarRaj Koothrappali
  • Kevin SussmanStuart Bloom