Sheldon feels lost after one of his favorite TV shows gets canceled too soon and Amy tries to help him get over his compulsive need for closure. Meanwhile, Raj discovers a secret about his new love interest, Lucy.
Sheldon has Penny as a guest on a "Fun with Flags" episode and she gets him to attend her acting class' presentation of "A Streetcar Named Desire". Raj drops out after Lucy unexpectedly leaves their first get together.
After an aborted girls' trip to Vegas, they are all playing Dungeons and Dragons together. Raj leaves after he finds that Lucy is free and he pushes her to do things that scare her. In the game, Penny casts a love spell on Sheldon and Amy's characters which gets Amy very upset because they are treating her and Sheldon's relationship as a joke.moreless
The couples are getting for Valentines' Day. Leonard, Penny, Howard and Bernadette are going to dinner. Sheldon and Amy are trying to get the perfect gifts for each other. Raj and Stuart are planning a singles only party at The Comic Book Store.
Thanksgiving plans include dinner at the Wolowitz home but Sheldon is less than pleased about the location. Penny’s past comes back to haunt her.
Leonard gets a new job opportunity to work abroad for the summer and Sheldon is feeling a little bit jealous. Meanwhile, Raj tries to move his relationship with Lucy into a new direction by introducing her to his friends, but he fears that she may not like them.
Raj and Lucy have their first date meeting in a library and texting to each other. The guys have to promote science careers for women at Howard's old middle school, while the girls go to Disneyland and get made up as Disney Princesses.
Sheldon gets all the guys before the Human Resources Department when he tries to talk to Alex about her advances to Leonard. Alex's actions also make Penny feel insecure.
Bernadette prepares a dinner for the gang, however Sheldon brings his own Thai take-out food after she makes Sheldon's Thai food from scratch. Sheldon rearranges Howard and Bernadette's closet and finds an unopened letter from Howard's father, sent for his 18th birthday. Penny and Leonard decide to invite the gang for a formal dinner party.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.
Raj wrestles with dating two women at the same time, Penny is offered a part in a trashy movie and Sheldon can't decide between two gaming systems.
When Stephen Hawking visits Caltech to give a lecture, Sheldon goes to great lengths for a chance to meet his hero in person.
Professor Proton pays Sheldon a visit after Sheldon suffers a tragic loss. Meanwhile, Leonard can't help competing with Penny when they reach a milestone in their relationship, and Amy and Bernadette treat the guys by making them a Star Wars Day gift.
When Sheldon and Leonard learn their favorite TV scientist is available to hire, they seek to do so. Howard and Bernadette are tasked with watching Raj's dog.
Sheldon is forced to work with Kripke and while in competition with Kripke, ends up spreading rumors about his sexual relationship with Amy. Howard and Raj get action figures of themselves that cost $1000.
Raj and Howard double-date and the latter is flushed with embarrassment after Raj's girlfriend reveals a secret she knows about Howard. Meanwhile, Sheldon is at loose ends when he begins to believe he's wasted his life trying to prove string theory.
Howard and Bernadette have a tense dinner with both of her parents. The subject of Mr. Rostenkowski's weekend fishing trip comes up and Howard is hooked into going with him. The guys visit Penny to learn all about fishing since she used to go with her dad. Sheldon shows up at Amy's apartment to find his girlfriend sick. After initially rejecting her request, Sheldon stays to take care of Amy the way his mother took care of him, sometimes a bit intimately.moreless
With Leonard mad at Sheldon, he moves in with Penny. Amy notes that she would be the perfect roommate for Sheldon since she knows him so well and he wouldn't have to break in someone else. Sheldon and Penny are not happy with these arrangements. Raj is trapped in the Wolowitz house with Howard's lonely mother.moreless
Guys plan to play Dungeons and Dragons, but girls are not invited, which causes arguments among them and the girls. After playing for some time at the apartment, the girls show up dressed sexily for a girls' night out and Raj goes with them to the nightclub.
When Professor Proton seeks advice from Leonard, Sheldon is hurt and contacts Bill Nye. Howard interrupts Raj’s girls night out.
In the Season 7 finale, Sheldon gets caught up in all the life-altering changes going on around him and considers a monumental move.
A successful gene experimentation leaves Sheldon excited to procreate with Amy, and he pulls out all stops to get her on board. Meanwhile, Raj is reluctant to reveal what the new woman in his life does for a living.
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
Sheldon hires an assistant. Amy gets incredibly jealous of Sheldon having a female assistant, but Alex is actually more interested in Leonard. Meanwhile, Wolowitz' return from space has been delayed a week and he starts to lose his mind because of it.
Competition between the guys increases when a slot for a tenured professor opens up and they start to schmooze the tenure committee members that include Mrs. Davies from Human Resources who Sheldon has crossed paths with before.
While her apartment is being fixed due to a flood, Amy decides to move in with Sheldon, who sees this as a scientific experiment. Meanwhile, Howard and Bernadette find out that Raj knows what sex their baby is and they wonder whether or not they want to know.
Leonard finds himself drawn towards a comely comic book illustrator. Meanwhile, Sheldon tries to scare the gang for Halloween.
As Howard awaits blast-off, he recounts how the gang threw together a last-minute wedding for him and Bernadette.
With Sheldon rattled and impossible to be around after meeting Dennis, a 15-year-old physicist who's smarter than he, the rest of the guys search for a way to eliminate the threat.
Leonard and Sheldon each lie to avoid hearing Penny sing in a production of Rent. However, Sheldon's lie becomes a bit too complicated for its own good.
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.
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
A trying day at the movie shoot leaves Penny with questions about her life choices, so she decides to act on it; and caring for a bedridden Mrs. Wolowitz proves a challenge for Howard and Bernadette. Meanwhile, Sheldon offers relationship advice to Raj after he sees Emily at the movies with another man.moreless
A bachelor party and his sexual past puts Howard's marriage to Bernadette in jeopardy.
Raj and Howard try to figure out Sheldon's secret daily afternoon routine. Meanwhile, jealousy takes over Leonard and Penny's relationship.
Sheldon finds out that the repairs to Amy's apartment have been completed for weeks, while Leonard discovers that Penny has been removing his collectibles from the apartment.
Sheldon's getting fired forces him to explore what life has to offer outside physics, leaving Leonard to take drastic action to snap his friend out of his funk.
Sheldon finds himself jealous when Amy goes on a date with Stuart. The other guys can't resist the allure of the latest collectable card game expansion pack.
Sheldon once again has to keep a secret when he learns Leonard and Penny are going to break up. Howard keeps getting teased by his fellow astronauts in space.
Sheldon goes through a hard time because of the attention of his newly discovered element. Also, Raj stays over at Howard's house creating some marriage tension between Howard and Bernadette.
Leonard asks Penny out on an impromptu romantic date.
Wolowitz is caught in an argument between Bernadette and his mom, even while he's in space. Meanwhile, with his friends on dates, Raj feels lonely.
Amy and Bernadette organize a prom to be held atop the guys' apartment complex, but Sheldon is leery of all the prom pomp, circumstance and romancing that goes with it.
Bernadette tries to decrease the amount of friction in Howard and Sheldon's friendship. Penny's car breaks down and she is afraid she will have to return to The Cheesecake Factory.
Penny finds the perfect girl for Raj to date. Meanwhile, Sheldon uses Dungeons & Dragons dice to make life's trivial decisions.
Sheldon is aghast to learn the new chair in Penny's apartment was someone else's garbage. Leonard and Priya try a long-distance relationship.
Sheldon faces a crisis of conscience after breaking a Star Trek toy given to him by Penny. Meanwhile, a lonesome Raj is smitten after a date set up by his parents.
Sheldon irks the gang over his obsession with proper Christmas gift protocol. Leonard is crushed when Penny dates a colleague of his.
Leonard buys a dining room table which causes Sheldon to reevaluate the changes in his life. Meanwhile, Howard is offered a chance to go back to space and Bernadette struggles with whether or not to encourage him.
Sheldon incurs Amy's ire when he chooses a weekend of videogaming with the guys over a birthday party for her aunt.
While Sheldon and Howard continue their bonding holiday to Houston, Texas, Sheldon's surprise visit to see his Mommy forces him to start addressing a new reality. Meanwhile the rest of the gang are subjected to a Raj's surprise "Murder Mystery" party that leads the gang to speculate where they might all be 20 years from now.moreless
Problems arise between Amy, Penny and Bernadette because Sheldon tried something new and spontaneous. Howard provides assistance to Raj regarding his date Emily.
Penny's flirtatious sales pitch is misunderstood by a doctor-client, while Bernadette and Amy debate whether female scientists ought to play the sexuality card.
When it is revealed that Penny and Bernadette went wedding dress shopping without her, Amy becomes heartbroken and pressures Sheldon for sex.
Brilliant physicist roommates Leonard and Sheldon meet their new neighbor Penny, who begins showing them that as much as they know about science, they know little about actual living.
Sheldon is miffed that Leonard plans to attend a party hosted by his nemesis, Wil Wheaton. Meanwhile, Howard is offered a chance to be a payload specialist on the International Space Station.
Sheldon and Raj undertake an underground research expedition that turns into a test of how long before they get under each other's skin. Meanwhile, Leonard and Penny argue about money, and go to Howard and Bernadette for advice.
An online troll rips Leonard and Sheldon's published physics paper, so the guys rally to defend the two and expose the bully, while a girls night out leads to Penny, Amy and Bernadette dishing about embarrassing past events.
After spending the night with Raj, Penny is worried that her friendship with the guys is in jeopardy, while Sheldon becomes the paintball team leader.
While trying to meet the Air Force deadline, Sheldon tries an energy drink for the first time and starts to believe he has become an addict. Meanwhile, Amy takes Penny to a party thrown by one of her colleagues and Bernadette thinks something is wrong with her as she's not as excited for her new baby as everyone else is.moreless
The gang talks about what they did over the holidays. Sheldon and Amy go to visit Sheldon's mom, who is thrilled that they are living together, which confuses Sheldon. Leonard and Penny go through a hard time getting their Christmas tree and Howard and Bernadette have a hard time getting their baby to stop crying.moreless
When Sheldon hinders progress on the guidance-system project, Leonard comes up with a plan to get rid of him by giving him tickets to a historic railroad. Meanwhile, Penny and Amy take new-mommy Bernadette on a girls' night out, leaving baby Halley in the hands of Raj and Stuart.
Leonard and Penny create lists of 'bugs' in their relationship in an attempt to strengthen it. Meanwhile, Sheldon and Amy create a YouTube video series called Fun with Flags, and Raj develops an unhealthy attachment to Siri on his iPhone.
Sheldon is ordered to teach a class, and the gang is surprised when Howard signs up to take it; and tensions between Penny and Bernadette afford Amy an opportunity to play one against the other.
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.
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.
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.
When his mother comes for another visit, Sheldon is disappointed that she's stopped being the mother he wants her to be.
Sheldon is intrigued with the of beta testing an MIT designed machine that purports to help read people’s emotions. Leonard tries to hide his anger when Penny announces that her brother is coming to town and staying with them and Raj invites his ex-girlfriends to give him dating advice.
Leonard needs surgery for a deviated septum, and Sheldon gets his nose out of joint because he feels an operation is too dangerous and that his roommate may not make it out alive. Meanwhile, a distraught Raj learns his parents have divorced on the eve of their 40th anniversary.
Before he's about to be interviewed for a documentary created by Leonard Nimoy's son, Sheldon reveals to Leonard and Penny that he was going to propose to Amy before she broke up with him and they try to convince him to admit that he's hurt. Meanwhile, Bernadette plans on renovating the house and Howard is not too happy about it.moreless
The guys heads are in a spin when an Air Force bigwig approaches them about their revolutionary gyroscope invention; and Bernadette is upset with Penny after she accidentally leaks a secret to Bernadette's coworkers about her being pregnant.
Sheldon finds himself in hot water when he doesn't appreciate Amy's recent accomplishment. Howard discovers Bernadette doesn't interact well with children.
Sheldon is forced into altering his precious schedule after his barber falls ill. Meanwhile, the training required to be an astronaut has Wolowitz wondering if he has the right stuff.
When the University reassigns Sheldon's parking spot to Wolowitz, their fight affects the whole gang.
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.
A geologist coworker's MacArthur Genius fellowship award leaves Sheldon stone cold jealous. Meanwhile, Howard stumbles upon a remote-control Stephen Hawking action figure that he invented. Hawking appears as himself.
Personalities collide when Sheldon and Leonard's mothers finally meet. Meanwhile, Howard finally decides to "man up" and do his fair share of the housework - but not without a little help from his friends.
As the chaotic possibility of a looming romantic relationship between Lenard's father and Sheldon's mother causes strife amongst the families, Howard's paranoia grows as he contemplates the desires of the U. S. Air Force towards him and his invention.
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.
Leonard can't take Sheldon's continued selfishness and agrees to dissolve the Roommate Agreement. Howard wants to have a cool nickname for when he's an astronaut.
While Raj eagerly awaits data from a space probe in which he was involved, Howard keeps distracting him. Later, dress shopping with Penny and Amy doesn't exactly prove to be a good fit for Leonard and Sheldon.
While Amy, Penny and Bernadette have a girls weekend in Vegas, Penny ends up having to study at the last minute, while Amy and Bernadette go out and get drunk. Back at home, with the girls gone, the four guys want to invent something new, but keep focusing on other things.moreless
Sheldon becomes concerned that his cushy lifestyle is impacting his professional progress and keeping him from achieving scientific renown, so he asks the gang to make life more difficult for him. Meanwhile, Howard invents an unflattering game about Raj.
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
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.
Amy is incensed when she discovers Sheldon has shared intimate relationship information with people at the university; and Raj is knocked for a loop when his father stops sending financial support.
When a new office space is made available, Sheldon goes head to head with his nemesis, Kripke, for the right to move in. Meanwhile, Penny is unsettled by painting given to her by Amy.
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
The time comes for Howard and Bernadette to have their baby and the gang all wait together at the hospital. Meanwhile, it is Amy's birthday and she and Sheldon plan on having their annual night of romance.
Wanting to go out with the guys, Sheldon foolishly pays Stuart to spend the day with Amy. Also, Penny struggles to connect with her new mother-in-law while Amy and Bernadette have no problem hitting it off with her.
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.
On Christmas Eve, Amy plans a traditional Victorian dinner, while Raj, Leonard and Howard scramble to remove a pigeon that flew into the clean room at the university. To prove a point to Amy, a Scrooge-like Sheldon buys her the worst possible gift.
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
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.
In the Season 8 premiere, Amy and Leonard take a surprise road trip to Arizona to retrieve Sheldon, while Penny goes on a job interview at Bernadette's company, and Howard has problems wrapping his head around Stuart's relationship with Mrs. Wolowitz.
Raj's brings his new girlfriend over to meet the gang, but she seems standoffish with Penny, who tries to figure out why. Meanwhile, the guys put their heads together to try to re-open Stuart's comic book store.
When Leonard is set to give the commencement address at his former high school, a canceled flight threatens to stop him giving the speech. Meanwhile, Howard's engineering skills are tested when he and Sheldon try fix Raj's toy helicopter, while Raj plays his parents against each other after his father cuts him off financially.moreless
The gang goes to a wine bar and runs into Penny's old boyfriend, Zack, who hits it off with Raj's girlfriend, Claire. Meanwhile, Bernadette and Sheldon spend an evening together.
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.
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.
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.
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.
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.
Forced to use his vacation time, Sheldon dabbles in biology in Amy's lab. Bernadette reveals to the girls that her father wants her to make Howard sign a pre-nup.
Feeling his fetal offspring kick sends Howard on a baby-items buying binge with Raj; Sheldon and Amy host a brunch in their new digs; and Penny, by virtue of her performance in Serial Ape-ist, is invited to a sci-fi convention.
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.
Leonard is hesitant when a bully from high school wants to meet for a drink. Meanwhile, Penny comes to realize she was a bully herself.
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.
Sheldon and Leonard fight when it comes to dividing up their joint possessions while Raj and Stewart trip over themselves in helping Bernadette during the final weeks of her pregnancy.
Leonard, Raj and Howard clean out the office of the deceased Professor Roger Abbot and find a bottle of champagne meant to be opened when he made his first great scientific discovery. Meanwhile, Sheldon prepares his final episode of "Fun with Flags". Bernadette discovers that people are afraid of her.
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.
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
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.
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.
A nervous Wolowitz is thrown for a loop when NASA asks him to toss out the first pitch at a Los Angeles Angels baseball game. Meanwhile, Sheldon brags that he and Amy are a better couple than Leonard and Penny, so they set out to prove he's way off base.
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.
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.