The Date Night Variable
E1
With his friends on dates, Raj must face his loneliness. Also, Wolowitz is caught in an argument between Bernadette and his mom, even while he’s in space.
The Decoupling Fluctuation
E2
When Sheldon learns that Penny is thinking about breaking up with Leonard, he tries to intervene. Meanwhile, in space, the other astronauts pick on Howard.
The Higgs Boson Observation
E3
Amy feels threatened when Sheldon hires a young female assistant, and the pressure of being in space takes its toll on Wolowitz.
The Re-Entry Minimization
E4
When Wolowitz returns from space, he doesn’t get the hero’s welcome he expected. Meanwhile, Game Night turns into a battle of the sexes.
The Holographic Excitation
E5
The gang celebrates Halloween at Stuart’s comic book store. Meanwhile, Leonard seduces Penny with science.
The Extract Obliteration
E6
Sheldon’s relationship with Stephen Hawking is threatened over a game of “Words with Friends,” and Penny secretly enrolls in a class at the local college.
The Habitation Configuration
E7
Wolowitz struggles with moving out of his mother’s house. Meanwhile, Sheldon is caught in the middle of an argument between Amy and Wil Wheaton.
The 43 Peculiarity
E8
Raj and Howard try to to figure out why Sheldon disappears at 2:45 every afternoon; jealousy arises in Penny and Leonard's relationship.
The Parking Spot Escalation
E9
When the University reassigns Sheldon’s parking spot to Wolowitz, their fight affects the whole gang.
The Fish Guts Displacement
E10
When Amy gets sick, Sheldon tries to nurse her back to health; Wolowitz and his father-in-law plan a fishing trip.
The Santa Simulation
E11
During a Dungeons and Dragons game, Sheldon revisits Christmas memories; Amy, Penny and Bernadette look for a date for Raj.
The Egg Salad Equivalency
E12
When Sheldon is accused of sexual harassment, he ends up getting Raj, Leonard and Howard in trouble.
The Bakersfield Expedition
E13
As the guys don costumes and go on a road trip to a comic book convention, the ladies decide to stay home and try to interpret a comic book.
The Cooper/Kripke Inversion
E14
Sheldon faces a crisis of confidence when he is forced to work with his nemesis, Barry Kripke; Raj and Howard buy expensive action figures of themselves.
The Spoiler Alert Segmentation
E15
A fight between Sheldon and Leonard impacts Amy and Penny's living arrangements; while Howard is away, Raj helps Mrs. Wolowitz out.
The Tangible Affection Proof
E16
The guys search for a perfect Valentine's Day gift for their significant others; Stuart and Raj host a "lonely people" party at the comic book store.
The Monster Isolation
E17
After a bad date, Koothrappali decides to never leave his apartment; Penny's acting skills impress Sheldon.
The Contractual Obligation Implementation
E18
Leonard, Sheldon and Howard give lectures on science to junior high students. The girls ditch work to go to Disneyland. Raj devises a date for Lucy that fixes their social anxiety problems.
The Closet Reconfiguration
E19
Howard considers whether or not he should open a letter from his father; Penny and Leonard host a "grown-up" cocktail party.
The Tenure Turbulence
E20
The girls get involved when Leonard, Sheldon and Raj compete for tenure at the University.
The Closure Alternative
E21
Amy tries to help Sheldon get over his compulsive need for closure when one of his favorite TV shows is canceled; Raj discovers a secret about Lucy.
The Proton Resurgence
E22
Leonard and Sheldon hire the host (Bob Newhart) of their favorite childhood TV show to perform; Bernadette and Howard run into trouble while dog-sitting for Raj's pet.
The Love Spell Potential
E23
A date between Raj and Lucy takes both of them out of their comfort zones. After a trip to Las Vegas goes awry, the girls join in on a Dungeons and Dragons game, which causes Amy and Sheldon to re-evaluate their relationship.
The Bon Voyage Reaction
E24
When Leonard receives an exciting opportunity to work overseas, Penny and Sheldon are thrown for a loop. Raj and Lucy's relationship comes to a crossroad.