Tensions arise when both of Leonard's parents and Sheldon's mother arrive to attend Leonard and Penny's second wedding ceremony, as they were not at the first one is Las Vegas.
While out at a cabin in the woods, Sheldon, Leonard, Penny and Amy play a game of "Never Have I Ever" which reveals some of their deep dark secrets. Meanwhile, Howard starts to believe that Raj is getting way too involved with Bernadette's pregnancy and tries to think of the nicest way to tell him to stop.moreless
Sheldon's old laptop finally dies and Amy buys him a new one. Sheldon does not want to dispose of the old one so he takes it somewhere where he knows it will be safe. Meanwhile, Leonard and Howard sneak off to see a preview of Suicide Squad, leaving their wives to work on a project they were busy on.moreless
When filing for a patent for their infinite persistence gyroscope, Leonard, Sheldon, and Howard learn that the university owns 75% of the patent's revenue, so they decide to write a contract between the three of them to split the remaining 25%. Also, Raj looks to the ladies for advice when both Emily and Claire contact him.moreless
Sheldon has always hated birthdays due to many bad experiences when he was younger, so the gang tries to throw him the best birthday party ever, which includes getting Adam West to appear at the party.moreless
Bernadette shares with Howard that she's pregnant, but his reaction is not what she hoped for. The guys take Howard to a karaoke bar where they are joined by the girls to celebrate the news.moreless
Sheldon and Amy host a live Valentine's Day episode of "Fun with Flags", Leonard and Penny look for a way to enjoy Valentine's Day, Howard and Bernadette prepare to try out their new hot tub and Raj struggles with his feelings about Emily.moreless
Sheldon's grandmother, aka Meemaw, visits and there's friction between her and Amy, which intensifies after the elderly woman blurts out a secret about Sheldon. Meanwhile, Raj is conflicted when an attractive writer for a children's sci-fi show asks to collaborate with him.moreless
After the entire gang was abused by a sick Sheldon, they plan a weekend getaway without him. Meanwhile Sheldon, in his own way, sets out to apologize to everyone he mistreated.
Leonard helps Penny get an appointment with a psychiatrist in order to help her make a sale; after two years, Stewart moves out of Howard and Bernadette's house into his own apartment. Elsewhere, Sheldon and Raj discover a medium sized asteroid, then debate about what to call it.moreless
Sheldon plans a huge birthday surprise for Amy while Leonard, Raj and Howard take Wil Wheaton with them to see the new Star Wars movie.
Sheldon goes crazy trying to figure out the name of the song he can't get out of his head, much to the annoyance of Leonard and Penny. While this is going on, Raj and Howard create a fan page for their band, only to discover that only one person liked it and they try to set up a date to meet him.moreless
Leonard and Penny cook their first Thanksgiving dinner as a married couple, Sheldon and Amy, as friends, visit an aquarium and Howard, Bernadette, Raj and Emily volunteer at the local soup kitchen.
When Leonard, Penny and Bernadette learn that Amy is going out on a dinner date, the trio set out to spy on her and the guy. Meanwhile, Sheldon recruits Raj and Howard to find a woman for him, since they were responsible for getting Amy and he together.moreless
As a Swedish team threatens to beat Leonard and Sheldon to proving their own theory, they consider breaking some rules in order to be able to make their experiment. Meanwhile, Penny and Bernadette set a dating app on Amy's phone.moreless
Ken is asked to speak at a banquet honoring Dr. Kevin O'Connell, who just happens to be Allison's former boyfriend.
The guys want to learn to be better at sports so Barry Kripke teaches them fencing. Meanwhile the girls help Stuart try to get more women to come to the comic book store. Amy gets asked out by Stuart and Kripke but she turns them both down.moreless
When Leonard and Penny move in together, Sheldon is very upset and longs for an emotion-free life like what he had in 2003. Meanwhile, Howard and Raj attempt to form a band.
The guys get together to throw Leonard a bachelor party in Mexico only to have car trouble put a damper on their plans. Meanwhile, Bernadette and Amy urge Penny to tell her parents that she is married.moreless
Leonard and Penny are still having problems with their new marriage while Sheldon comes up with a few ways to get revenge on Amy for breaking up with him.
Penny and Leonard deal with Leonard's confession on the way down the aisle while Sheldon struggles to understand Amy's decision to take a step back from their relationship.
In the Season 8 finale, Leonard and Penny are pressured to set a wedding date by Sheldon, whose relationship with Amy has taken an interesting turn.
When Raj is asked to submit a proposal to NASA, the guys end up in a fight. Penny wonders what to do when she asked to audition for a movie role.
When Sheldon and Amy build a blanket fort, they come to major crossroads in their relationship. Also, Wolowitz meets the half-brother he never knew he had, and when Penny is invited to appear on Wil Wheaton's podcast, she and Leonard have a huge, on-air argument.moreless
A speaking engagement at UC Berkeley puts Leonard and Sheldon in a galaxy not too far, far away from their idol George Lucas' Skywalker Ranch, and they consider dropping by. Meanwhile, Howard and Bernadette argue over what to do with his Doctor Who TARDIS, so Raj and Amy try to settle things with a game of table tennis.moreless
An electrical short thaws the last meal that was cooked by Mrs. Wolowitz, and the gang ponders what to do with it, while Sheldon and Leonard's work is featured in a magazine, but only one receives credit.moreless
There's trouble in paradise when Amy discovers Sheldon signed up for a one-way mission to colonize Mars, and the two get into a dogfight at a pet store. Meanwhile, Leonard makes a very "adult" purchase for Penny; and Emily catches Raj snooping in her apartment.moreless
As a joke, Sheldon and Penny try an experiment designed to make participants fall in love. Also, Leonard, Amy, Raj and Emily spend the evening trying to escape a room with a "zombie." And, after returning from Mrs. Wolowitz' funeral, Bernadette and Howard run into trouble at the airport.moreless
Amid the excitement of Stuart reopening his comic-book store, Howard gets some unsettling news; and after teaching Sheldon how to "let it go," Penny doesn't practice what she preaches when she learns something maddening about Amy. Meanwhile, Raj and Leonard run into a restaurant customer who looks a lot like actor Nathan Fillion.moreless