The Big Bang Theory Season 5 Complete Pack Official

: Amy Farrah Fowler (Mayim Bialik) and Bernadette Rostenkowski (Melissa Rauch) are promoted to main characters, providing a female social circle for Penny that mirrors the guys' group.

: The milestone episode, "The Recombination Hypothesis," sees Leonard and Penny attempt a "beta test" of their relationship after their initial breakup, marking a central narrative shift for the series. The Big Bang Theory Season 5 Complete Pack

: Sheldon and Amy formalize their unique bond with a "Relationship Agreement," while Howard and Bernadette prepare for their wedding, culminating in Howard's mission to the International Space Station. : Amy Farrah Fowler (Mayim Bialik) and Bernadette