The Alien Parasite Hypothesis

Amy crushes on one of Penny's dim ex-boyfriends, Zack. Raj and Wolowitz argue over who'd be the better superhero.

Season 4 | Episode 10
TV-14-DL
PRESENTED BY
Cast

Jim Parsons

Sheldon Cooper

Johnny Galecki

Leonard Hofstadter

Kaley Cuoco

Penny

Simon Helberg

Howard Wolowitz

Kunal Nayyar

Raj Koothrappali