Episode 1 | The Conjugal Conjecture

As Leonard and Penny attempt to hold another wedding ceremony everyone can attend, they have to deal with Penny's family arriving and Leonard's father spending the night with Sheldon's mother.

Episode 2 | The Military Miniaturization

Howard is visited by an Air Force colonel regarding his invention. Penny accidentally lets it slip about Bernadette's pregnancy to their co-workers.

Episode 3 | The Dependence Transcendence

Bernadette confesses to Raj that she isn't sure if she's ready to be a mother, Penny accompanies Amy to a university mixer, and Sheldon goes to unusual extremes to assist Howard with his military project.

Episode 4 | The Cohabitation Experimentation

When Amy must vacate her apartment for repairs, living arrangements are made with Leonard, Sheldon, and Penny. Howard and Bernadette don't want to know the sex of their baby, but Raj finds out.

Episode 5 | The Hot Tub Contamination

Sheldon and Amy go through a period of adjustment with their new living arrangement. Howard and Bernadette are forced to vacation at home when she falls ill and keep it a secret, unaware Raj and Stuart planned to use their hot tub.

Episode 6 | The Fetal Kick Catalyst

Sheldon and Amy host a brunch. Penny is surprised by her popularity when her movie, "Serial Ape-Ist" is featured at a Van Nuys comic book convention. Howard starts to freak out about parenthood after feeling the baby kick for the ...

Episode 7 | The Veracity Elasticity

Amy doesn't tell Sheldon her apartment has been repaired. Leonard finds out Penny is slowly moving all of his collectible toys into storage.

Episode 8 | The Brain Bowl Incubation

A successful gene experimentation leaves Sheldon excited to procreate with Amy, and he pulls out all stops to get her on board. Meanwhile, Raj takes an interest in the cleaning lady at the university.

Episode 9 | The Geology Elevation

Sheldon can't contain his jealousy when Bert wins a grant for his geology research. A distasteful toy built by Howard faces judgement from the gang.

Episode 10 | The Property Division Collision

Dividing up their possessions becomes an all-out war between Leonard and Sheldon. Stuart asks to live with Howard and Bernadette and tries to supplant Raj's efforts to help with the new baby.

Episode 11 | The Birthday Synchronicity

Amy's desire to have an intimate night with Sheldon on her birthday is interrupted by Bernadette going into labor.

Episode 12 | The Holiday Summation

After spending the holidays apart, the gang get together to hear about Sheldon's and Amy's trip to Texas, Leonard's and Penny's Christmas tree adventure, and Howard's and Bernadette's first days as parents.

Episode 13 | The Romance Recalibration

Leonard and Penny ask for Sheldon's and Amy's help on putting the romance back in their marriage. Howard and Raj go to extreme lengths to stop the floor in Halley's bedroom from making noise.

Episode 14 | The Emotion Detection Automation

Penny wants to help her brother get a job with her company. Sheldon learns of a machine that will help him understand human emotions. Raj reunites some of his old girlfriends to figure out why he is still single.

Episode 15 | The Locomotion Reverberation

Leonard and Howard's attempt to keep Sheldon away from their Air Force project by sending him on a train trip backfires. Penny and Amy take Bernadette for her first night out since having the baby.

Episode 16 | The Allowance Evaporation

Sheldon and Amy have their first fight since moving in together. Meanwhile Raj is shocked at the reality of financial independence when he stops receiving support from his father.

Episode 17 | The Comic-Con Conundrum

The guys' annual trip to Comic Con is in doubt when Raj can't afford to go.

Episode 18 | The Escape Hatch Identification

When the gang offer places for Raj to live, it creates unexpected conflict among everyone.

Episode 19 | The Collaboration Fluctuation

Leonard, Penny and Raj adjust to their new living arrangements; Sheldon expresses an interest in Amy's work.

Episode 20 | The Recollection Dissipation

Sheldon reaches his limit when he works on projects with Leonard, Howard and Amy in one day. Bernadette has doubts about leaving Halley when she goes back to work.

Episode 21 | The Separation Agitation

Howard and Bernadette have a hard time leaving Halley in daycare when Bernadette returns to work. Bert introduces the gang to his new girlfriend.

Episode 22 | The Cognition Regeneration

Leonard is less than thrilled when Penny considers accepting a job offer from her ex-boyfriend, Zack. Sheldon worries that he hasn't reached his full potential soon enough.

Episode 23 | The Gyroscopic Collapse

After celebrating the completion of the top-secret Air Force project, Leonard, Sheldon and Howard get an unwelcome surprise; Amy receives an offer for a summer position at Princeton as a visiting researcher.

Episode 24 | The Long Distance Dissonance

The gang become concerned when Sheldon's former admirer, Ramona Nowitzki, resurfaces while Amy is away at Princeton.