This Broadcast
The Big Bang Theory
8:00 pm - 8:30 pm Monday, September 21
The Alien Parasite Hypothesis
Season 4 · Episode 10
Amy finds she has romantic feelings for Penny's former boyfriend Zack, while Raj and Howard begin competing to prove which of them would make the better superhero. Comedy, guest starring Brian Thomas Smith
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Cast & Crew
The Big Bang Theory Cast & Crew
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- Johnny Galecki — Actor as Leonard Hofstadter
- Jim Parsons — Actor as Sheldon Cooper
- Kaley Cuoco — Actor as Penny
- Simon Helberg — Actor as Howard Wolowitz
- Kunal Nayyar — Actor as Raj Koothrappali
- Mayim Bialik — Actor as Amy Farrah Fowler
- Brian Thomas Smith — Actor as Zack
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