Episode 1 | The Proposal Proposal

Amy has trouble deciding whether or not she should marry Sheldon. Meanwhile, Bernadette confides in Penny when she finds out some huge news.

Episode 2 | The Retraction Reaction

Leonard angers the University and the Physics Community when he gives an embarrassing radio interview. Bernadette and Amy compare their successes at work.

Episode 3 | The Relaxation Integration

Sheldon and Amy struggle with picking a wedding date. Meanwhile, Stuart and Raj fight over one of Bernadette's co-workers for a date.

Episode 4 | The Explosion Implosion

Howard and Bernadette are disappointed when they find out the sex of the baby. Leonard is annoyed when his mother befriends Penny.

Episode 5 | The Collaboration Contamination

Amy and Howard work in the lab together causing Sheldon, Bernadette and Raj to feel jealous and lonely. Penny starts using a parenting book to control Sheldon's behavior.

Episode 6 | The Proton Regeneration

Sheldon and Wil Wheaton both go head-to-head for the role of the new Professor Proton, Meanwhile Penny takes care of Halley when Bernadette and Howard are on bed rest.

Episode 7 | The Geology Methodology

When Bert asks Sheldon to collaborate on a project with him, Sheldon becomes worried about others finding out because he thinks geology is beneath him. Raj seeks advice after reconnecting with Ruchi.

Episode 8 | The Tesla Recoil

Howard and Leonard become upset after they discover that Sheldon has been working with the military without telling them; Bernadette asks Raj to investigate her suspicions that Ruchi is attempting to take her job away from her.

Episode 9 | The Bitcoin Entanglement

Sheldon tries to teach the other guys a lesson after they cut him out of a potentially valuable Bitcoin investment seven years ago.

Episode 10 | The Confidence Erosion

Sheldon and Amy try to eliminate stress from wedding planning by applying math to the process. Raj and Howard come to blows when Raj begins to feel like Howard hurts his confidence.

Episode 11 | The Celebration Reverberation

Raj and Howard's feud continues as the gang plan Halley's first birthday party. Sheldon's surprise for Amy's birthday goes awry when they get food poisoning.

Episode 12 | The Matrimonial Metric

Sheldon and Amy pick their best-man and maid of honor by experimenting on the gang. Meanwhile, Leonard's self-confidence is still badly damaged after reading his brother's Christmas letter.

Episode 13 | The Solo Oscillation

Sheldon kicks Amy out of the apartment to work solo, and she and Leonard end up bonding during a series of science experiments; Howard is replaced by Bert in Footprints on the Moon.

Episode 14 | The Separation Triangulation

Raj meets a girl at the Planetarium, but soon after finds out she is married. Sheldon rents out his old room to use for his work.

Episode 15 | The Novelization Correlation

Leonard's book raises questions, and Amy guest stars on the new Professor Proton show.

Episode 16 | The Neonatal Nomenclature

When Bernadette won't go into labor, the gang try different tactics to get things started. Also, Wolowitz confronts Bernadette after Amy accidentally reveals she's already chosen their son's name.

Episode 17 | The Athenaeum Allocation

Leonard jumps through hoops to help secure the perfect wedding venue for Sheldon and Amy. Also, Bernadette and Wolowitz have a hard time deciding who should stay at home with the kids and who should go back to work.

Episode 18 | The Gates Excitation

Leonard, Howard and Raj try to meet Bill Gates, who's meeting with Penny to merge their companies; Sheldon thinks he's the victim of an April Fool's prank.

Episode 19 | The Tenant Disassociation

Leonard runs against Sheldon to be president of the tenants association; Wolowitz and Koothrappali find a drone in the backyard.

Episode 20 | The Reclusive Potential

Sheldon takes the guys to a cabin in the middle of nowhere to meet a reclusive scientist; Penny and Bernadette improvise Amy's bachelorette party.

Episode 21 | The Comet Polarization

Sheldon's comic book store experience changes when writer Neil Gaiman puts Stuart's store on the map; friendships are threatened when Koothrappali takes credit for Penny's astronomical discovery.

Episode 22 | The Monetary Insufficiency

Sheldon goes to Vegas to win money for science. Also, Penny and Bernadette take Amy wedding dress shopping, but her terrible choice entangles them in a web of lies.

Episode 23 | The Sibling Realignment

Sheldon and Leonard make a road trip to wrangle a reluctant wedding guest.

Episode 24 | The Bow Tie Asymmetry

When Amy's parents and Sheldon's family arrive, everybody is focused to make sure all wedding arrangements go according to plan - everyone except the bride and groom.