KoothrappaliВ 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, Koothrappali & Wolowitz try to relive the good old days after Wolowitz buys a Vespa scooter that looks like the one he had years ago. The concept of what it'd mean for women everywhere if Amy were to win a Nobel Prize causes Amy to have a meltdown. Bernadette wants to write a children's book about Howard's trip to outer space and him over coming his fears. Sheldon and Amy are still fighting for recognition of their Super-Asymmetry theory while their rivals are on a media tour. Sheldon gets into doing experiments on the Wolowitz children. When 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.Д«ernadette and Penny go off to a conference while Howard is left watching their kids. Howard, Raj, and the girls turn the canceled bachelor party in a trip aboard the 'Vomit Comet'. Penny tries to seduce an abstaining Leonard to ruin his 'donation' for her ex-boyfriend, Zack, and his wife, Marissa.

Leonard is excluded from a scientific project. Sheldon helps the Wolowitzes with some paperwork until he finds them in an illegal venture. Also, Bernadette has a big success at work and Penny's going to be a part of it, whether she wants to or not. Campbell from Chicago, they're thrilled, until they try to kick Amy off the Nobel Prize nomination. When Sheldon & Amy's super-asymmetry theory is proven by two physicists, Dr. Also, Raj attempts to mend things with Anu. PennyвЂ™s ex-boyfriend, Zack, and his wife want a baby, but when Zack is infertile, they ask Leonard for help. Also, Raj catches Anu with her ex-boyfriend, and Stuart doesn't want to move in with Denise. Penny and Leonard organize a paintball game that results in mayhem when Sheldon is jealous of Amy. Also, Bernadette turns into a pageant mom when she tries to help Wolowitz ace his Magic Castle audition. Sheldon and Amy are still down about their theory being disproved, but a VHS tape from Sheldon's past inspires him not to give up. Bernadette tries to beat Howard and Raj at Fortnite, and recruits help from Denise. He finds a Russian paper that basically discredits super-asymmetry. Leonard researches citations for Sheldon and Amy's paper.

Also, Raj and Anu to get physical for the first time. Fowler away with magic tricks, Sheldon has no choice but to bond with Mrs. Also, Bernadette turns the backyard playhouse into a hideaway from her husband and kids. Leonard is caught between a rock and a hard place when he's responsible for distributing extra grant money.

Also, Leonard is shocked that Penny doesn't remember their first kiss. When Wolowitz dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny's Halloween party. Also, Raj doesn't want Howard to join him in hosting a show at the planetarium. 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. Also, Bernadette and Penny take out Raj's fiancГ©e, Anu, for dinner to get the skinny on her. When Sheldon won't tell anyone why he's never mentioned Tam, his childhood best friend, Leonard takes matters into his own hands. Also, Penny and Leonard talk about starting a family while Koothrappali explores an arranged marriage. The Wolowitzes' life gets complicated when Stuart starts bringing his new girlfriend home. Stuart gets the nerve up to ask Denise out on a date, Leonard and Penny give Sheldon and Amy a strange wedding gift and Raj asks his father to find a wife for him. The Coopers are on their honeymoon in New York City, the Hofstadters find Larry Fowler hiding in Shamy's apartment and Raj has a Twitter fight with Neil deGrasse Tyson, which also gets Bill Nye involved.

Big bang theory s12 e18