S12E1 - The Conjugal Configuration
Sheldon and Amy's honeymoon runs aground in New York. Penny and Leonard discover they are uncomfortably similar to Amy's parents. Raj insults physicist Neil deGrasse Tyson and starts a Twitter war.
S12E2 - The Wedding Gift Wormhole
Sheldon and Amy drive themselves crazy trying to figure out what 'perfect gift' Leonard and Penny gave them for their wedding. Raj decides he wants to settle down and asks his father to arrange a marriage for him.
S12E3 - The Procreation Calculation
The Wolowitzes' life gets complicated when Stuart starts bringing his new girlfriend home. Also, Penny and Leonard talk about starting a family, while Raj explores an arranged marriage.
S12E4 - The Tam Turbulence
When Sheldon won't tell anyone why he's never mentioned his childhood best friend, Leonard takes matters into his own hands. Bernadette and Penny take out Raj’s fiancée for dinner to get the skinny on her.
S12E5 - The Planetarium Collision
When Amy doesn’t have time to work on super-asymmetry, Sheldon goes to great lengths to ensure she’s available to work with him even it if means accidentally sabotaging her career in the process. Raj doesn’t want Howard to join him in hosting a show at the planetarium.
S12E6 - The Imitation Perturbation
When Howard dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny's Halloween party. Leonard is shocked that Penny doesn't remember their first kiss.
S12E7 - The Grant Allocation Derivation
Leonard is caught between a rock and a hard place when he's responsible for distributing extra grant money. Bernadette turns the backyard playhouse into a hideaway from Howard and the kids.
S12E8 - The Consummation Deviation
Sheldon tries to bond with Amy's father, but when Howard lures Mr. Fowler away with magic tricks, Sheldon has no choice but to bond with Mrs. Fowler. Raj and Anu try to get physical for the first time.
S12E9 - The Citation Negation
Sheldon and Amy are devastated after learning from a Russian paper that Super Asymmetry has already been theorized and disproven. Meanwhile, ultra-competitive Bernadette asks Stuart’s girlfriend to teach her how to beat Howard in a popular video game.
S12E10 - The VCR Illumination
Sheldon and Amy are still down about their theory being disproven, but a VHS tape from Sheldon’s past inspires him not to give up. Bernadette turns into a pageant mom when she tries to help Howard ace his Magic Castle audition.
S12E11 - The Paintball Scattering
Penny and Leonard organize a paintball game that results in mayhem when Sheldon is jealous of Amy. Also, Koothrappali catches Anu with her ex-boyfriend, and Stuart doesn’t want to move in with Denise.
S12E12 - The Propagation Proposition
Penny’s ex-boyfriend, Zack, and his wife want a baby, but when Zack is infertile, they ask Leonard for help. Also, Koothrappali attempts to mend things with his ex-fiancée, Anu.
S12E13 - The Confirmation Polarization
Sheldon and Amy are thrilled when their super asymmetry theory is proven by two physicists, until they try to kick Amy off the Nobel nomination; Bernadette has a big success at work.
S12E14 - The Meteorite Manifestation
Sheldon is thrilled to help Bernadette and Wolowitz navigate bureaucratic paperwork, until he discovers they are breaking the law. Also, Leonard is disappointed when his friends exclude him from a scientific project.
S12E15 - The Donation Oscillation
Penny tries to seduce an abstaining Leonard to ruin his "donation" for her ex-boyfriend, Zack, and his wife, Marissa. Also, Wolowitz, Bernadette, Anu and Koothrappali turn Koothrappali's canceled bachelor party into a couple's trip.
S12E16 - The D & D Vortex
The gang finds out Wil Wheaton hosts a celebrity Dungeons and Dragons game involving William Shatner, Joe Manganiello, Kareem Abdul-Jabbar and Kevin Smith. Deception and betrayal are the path to make it to the one open seat.
S12E17 - The Conference Valuation
When Penny and Bernadette go to San Diego for a pharmaceutical sales convention, Wolowitz is in charge of the kids. Also, Sheldon finds a book on experimenting on kids, and the guys plus Amy make a day of it.
S12E18 - The Laureate Accumulation
When competitors Pemberton and Campbell charm America on a publicity tour, Sheldon and Amy try to bring Nobel laureates Kip Thorne, George Smoot and Frances Arnold to their side. Also, Halley's fear of the dark leads to opportunity and conflict for Howard, Bernadette and Stuart.
S12E19 - The Inspiration Deprivation
The concept of what it would mean for women everywhere if Amy were to win a Nobel Prize causes Amy to have a meltdown. Also, Koothrappali and Wolowitz try to relive the good old days after Wolowitz buys a scooter that looks like the one he had years ago.
S12E20 - The Decision Reverberation
Koothrappali is worried people won’t take him seriously in his own field after publishing a paper that suggests he may have discovered alien life. Also, Leonard wants to be the principal investigator on a plasma physics study.
S12E21 - The Plagiarism Schism
Kripke has proof that Dr. Pemberton plagiarized his thesis in college, and Sheldon and Amy aren't sure if they should turn him in or not; Wolowitz learns that Bernadette wasn't the only waitress at the Cheesecake Factory who had a crush on him.
S12E22 - The Maternal Conclusion
Leonard is pleasantly surprised when Beverly comes to visit and she's genuinely kind to him, until he finds out the real reason she's there. Also, Denise and Stuart overstay their welcome at the Wolowitz house.
S12E23 - The Change Constant / The Stockholm Syndrome
Sheldon and Amy await big news.
S12E24 - Unraveling the Mystery: A Big Bang Farewell
Johnny Galecki and Kaley Cuoco will lead fans on a trip down memory lane, sharing some of the best-kept backstage secrets and personal memories from the past 12 years.
