The Thespian Catalyst
Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.
The Love Car Displacement
Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.
The Wildebeest Implementation
Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.
The Roommate Transmogrification
When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she's regrets.
The Pirate Solution
Raj must find a new job or be sent back to India, but Sheldon has a solution, which leaves Leonard and Penny dealing with Howard as a third wheel.
The Gothowitz Deviation
Howard and Raj visit a Goth nightclub to pick up women while Sheldon attempts to build a better Penny using chocolate-based behavior modification.
The Jiminy Conjecture
Leonard and Penny struggle to recover from an awkward first hookup while Sheldon and Howard stake their best comic books on a bet to determine the species of a cricket.
The Bozeman Reaction
When their apartment is robbed, Leonard and Sheldon turn to their friends to create a state-of-the-art security system.
The Electric Can Opener Fluctuation
When Sheldon learns the guys tampered with his expedition data he got from the arctic, he leaves to Texas in disgrace. This results in the guys following him, which threatens Leonard's hope for some romantic time with Penny and the guys' friendship with Sheldon.
The Adhesive Duck Deficiency
With Leonard, Howard and Raj away camping in the desert, an injured Penny has only Sheldon to rely on.