The Plimpton Stimulation: When Sheldon meets a famous physicist online, he invites her over to the apartment, where she spends her time flirting with Leonard. (S3 Ep21) [AD,S]
The Citation Negation: Sheldon and Amy get some devastating news. Bernadette asks Stuart's girlfriend Denise to teach her how to beat Howard at a video game. (S12 Ep9) [AD,S]
The VCR Illumination: Sheldon and Amy are still upset about their theory being disproven, but a video tape from Sheldon's past inspires him not to give up. (S12 Ep10) [AD,S]
The Paintball Scattering: Jealousy, trust issues and tension among the couples in the gang cause mayhem when Penny and Leonard organise a paintball game. (S12 Ep11) [AD,S]
The Propagation Proposition: Penny's ex-boyfriend Zack and his wife want a baby, but when they encounter fertility problems, they ask Leonard for his help. (S12 Ep12) [AD,S]
The Confirmation Polarization: Sheldon and Amy are thrilled when their super-asymmetry theory is proved correct. Bernadette enjoys some big success at work. (S12 Ep13) [AD,S]
The Meteorite Manifestation: Sheldon is thrilled to help Howard and Bernadette with some bureaucratic paperwork, until he realises that they're breaking the law. (S12 Ep14) [AD,S]
The Conference Valuation: Penny and Bernadette go to San Diego for a sales convention, leaving Howard in charge of Michael and Halley while they're away. (S12 Ep17) [AD,S]
The Donation Oscillation: Penny attempts to sabotage Leonard's efforts to help her ex-boyfriend Zack and his wife Marissa have a family of their own. (S12 Ep15) [AD,S]
The Laureate Accumulation: When their academic competitors charm America on a publicity tour, Sheldon and Amy try to get some Nobel laureates on their side. (S12 Ep18) [AD,S]
The D & D Vortex: When the gang find out that Wil Wheaton is hosting a celebrity game of Dungeons & Dragons at his home, deception and betrayal take hold. (S12 Ep16) [AD,S]
The Inspiration Deprivation: Amy has a meltdown when she feels the pressure of what it would mean for women everywhere if she were to win a Nobel Prize. (S12 Ep19) [AD,S]
The Conference Valuation: Penny and Bernadette go to San Diego for a sales convention, leaving Howard in charge of Michael and Halley while they're away. (S12 Ep17) [AD,S]
The Decision Reverberation: Raj publishes a paper that suggests he may have discovered alien life. Penny encourages Leonard to stand up for himself. (S12 Ep20) [AD,S]
The Laureate Accumulation: When their academic competitors charm America on a publicity tour, Sheldon and Amy try to get some Nobel laureates on their side. (S12 Ep18) [AD,S]
The Plagiarism Schism: Barry Kripke finds proof that Dr Pemberton plagiarised his thesis in college. Should Sheldon and Amy turn in their rival? (S12 Ep21) [AD,S]
The Inspiration Deprivation: Amy has a meltdown when she feels the pressure of what it would mean for women everywhere if she were to win a Nobel Prize. (S12 Ep19) [AD,S]
The Maternal Conclusion: Leonard is surprised when his mother Beverly comes to visit and is kind to him, until he finds out the real reason she's there. (S12 Ep22) [AD,S]
The Decision Reverberation: Raj publishes a paper that suggests he may have discovered alien life. Penny encourages Leonard to stand up for himself. (S12 Ep20) [AD,S]
The Change Constant: Sheldon and Amy stay up late awaiting a phone call that could bring big news from the Nobel Committee: are their lives about to change? (S12 Ep23) [AD,S]
The Plagiarism Schism: Barry Kripke finds proof that Dr Pemberton plagiarised his thesis in college. Should Sheldon and Amy turn in their rival? (S12 Ep21) [AD,S]
The Stockholm Syndrome: Howard and Bernadette go on a trip without their children, Leonard and Penny try to keep a secret, and Raj makes a new friend. (S12 Ep24) [AD,S]
The Maternal Conclusion: Leonard is surprised when his mother Beverly comes to visit and is kind to him, until he finds out the real reason she's there. (S12 Ep22) [AD,S]
The Change Constant: Sheldon and Amy stay up late awaiting a phone call that could bring big news from the Nobel Committee: are their lives about to change? (S12 Ep23) [AD,S]
The Stockholm Syndrome: Howard and Bernadette go on a trip without their children, Leonard and Penny try to keep a secret, and Raj makes a new friend. (S12 Ep24) [AD,S]
The 21-Second Excitation: The gang's plans to attend a film screening are scuppered by Sheldon's nemesis Wil Wheaton. Penny and Bernadette invite Amy to her first slumber party. (S4 Ep8) [AD,S]
The Boyfriend Complexity: When Penny's father visits, Leonard discovers that her parents still think that he and Penny are a couple, so he takes advantage of the situation. (S4 Ep9) [AD,S]
The Conjugal Configuration: Sheldon and Amy's honeymoon runs aground, while Penny and Leonard discover that they are uncomfortably similar to Amy's parents. (S12 Ep1) [AD,S]
The Wedding Gift Wormhole: A stressed Sheldon and Amy struggle to work out what the 'perfect gift' is that Leonard and Penny gave them on their wedding day. (S12 Ep2) [AD,S]
The Conjugal Configuration: Sheldon and Amy's honeymoon runs aground, while Penny and Leonard discover that they are uncomfortably similar to Amy's parents. (S12 Ep1) [AD,S]
The Wedding Gift Wormhole: A stressed Sheldon and Amy struggle to work out what the 'perfect gift' is that Leonard and Penny gave them on their wedding day. (S12 Ep2) [AD,S]
The Thanksgiving Decoupling: Howard takes the gang to his mother's house for Thanksgiving to protect himself from his grumpy father-in-law who has also been invited. (S7 Ep9) [AD,S]
The Discovery Dissipation: Sheldon feels guilty when he gets attention for his accidental discovery of a new element. Raj stays with Howard and Bernadette for a week. (S7 Ep10) [AD,S]
The Cooper Extraction: Sheldon has to go back to Texas when his sister goes into labour. While he's away, the gang gather at the flat to decorate the Christmas tree. (S7 Ep11) [AD,S]
The Thanksgiving Decoupling: Howard takes the gang to his mother's house for Thanksgiving to protect himself from his grumpy father-in-law who has also been invited. (S7 Ep9) [AD,S]
The Hesitation Ramification: Penny's big TV acting break hits the cutting-room floor, so Leonard does his best to comfort her, which leads her to ask him a bold question. (S7 Ep12) [AD,S]
The Discovery Dissipation: Sheldon feels guilty when he gets attention for his accidental discovery of a new element. Raj stays with Howard and Bernadette for a week. (S7 Ep10) [AD,S]
The Cooper Extraction: Sheldon has to go back to Texas when his sister goes into labour. While he's away, the gang gather at the flat to decorate the Christmas tree. (S7 Ep11) [AD,S]
The Hesitation Ramification: Penny's big TV acting break hits the cutting-room floor, so Leonard does his best to comfort her, which leads her to ask him a bold question. (S7 Ep12) [AD,S]
The Sales Call Sublimation: Penny gets more than she bargained for when Leonard meets a psychiatrist, while Sheldon and Raj make an astronomical discovery. (S9 Ep12) [AD,S]
The Empathy Optimization: The gang plan a Sheldon-free weekend in Las Vegas after coping with his constant demands, rudeness and ingratitude when he was ill. (S9 Ep13) [AD,S]
The Meemaw Materialization: Sheldon is thrilled when his beloved grandma 'Meemaw' comes to visit, but his excitement fades when she butts heads with Amy. (S9 Ep14) [AD,S]
The Sales Call Sublimation: Penny gets more than she bargained for when Leonard meets a psychiatrist, while Sheldon and Raj make an astronomical discovery. (S9 Ep12) [AD,S]
The Valentino Submergence: Sheldon and Amy host a special live Valentine's Day episode of their internet show Fun with Flags. Leonard and Penny grapple with getting older. (S9 Ep15) [AD,S]
The Empathy Optimization: The gang plan a Sheldon-free weekend in Las Vegas after coping with his constant demands, rudeness and ingratitude when he was ill. (S9 Ep13) [AD,S]
The Positive Negative Reaction: When Bernadette makes a big announcement, Howard becomes convinced that he needs to start earning more money. (S9 Ep16) [AD,S]
The Meemaw Materialization: Sheldon is thrilled when his beloved grandma 'Meemaw' comes to visit, but his excitement fades when she butts heads with Amy. (S9 Ep14) [AD,S]
The Celebration Experimentation: The gang persuade Sheldon to celebrate his birthday and invite a few special guests along to his party, in the 200th episode. (S9 Ep17) [AD,S]
The Valentino Submergence: Sheldon and Amy host a special live Valentine's Day episode of their internet show Fun with Flags. Leonard and Penny grapple with getting older. (S9 Ep15) [AD,S]
The Application Deterioration: Leonard, Sheldon and Howard run into problems when they file for a patent. Emily reaches out to Raj after their break-up. (S9 Ep18) [AD,S]
The Positive Negative Reaction: When Bernadette makes a big announcement, Howard becomes convinced that he needs to start earning more money. (S9 Ep16) [AD,S]
The Celebration Experimentation: The gang persuade Sheldon to celebrate his birthday and invite a few special guests along to his party, in the 200th episode. (S9 Ep17) [AD,S]
The Application Deterioration: Leonard, Sheldon and Howard run into problems when they file for a patent. Emily reaches out to Raj after their break-up. (S9 Ep18) [AD,S]
The Lunar Excitation: Raj registers Sheldon for online dating and finds the perfect match: the female version of Sheldon. Penny seduces Leonard while she's drunk. (S3 Ep23) [AD,S]
The Robotic Manipulation: Penny tags along to Sheldon's first date with a woman he's been texting for months. Howard finds a new use for a robotic arm. (S4 Ep1) [AD,S]
The Cruciferous Vegetable Amplification: Sheldon realises that he won't live long enough to download his consciousness into a robot body, so he tries to extend his lifespan. (S4 Ep2) [AD,S]
The Zazzy Substitution: The guys are concerned when a heartbroken Sheldon starts bulk buying cats after he breaks up with Amy, so Leonard tries to get Sheldon's mother to visit. (S4 Ep3) [AD,S]
The Hot Troll Deviation: An embarrassing secret of Howard's comes to light as he tries to win back Bernadette. Sheldon and Raj have trouble working together. (S4 Ep4) [AD,S]
The Desperation Emanation: Leonard realises he's the only one of the gang with no girlfriend. Sheldon wants to get rid of his when she hatches a plan for him to meet her mother. (S4 Ep5) [AD,S]
The Irish Pub Formulation: A visit from Raj's sister Priya creates tension among the guys, especially when Leonard asks Sheldon to conceal his romantic past with her. (S4 Ep6) [AD,S]
The Apology Insufficiency: Leonard thinks his dating problems are due to a lack of confidence, and vows to be self-assured around attractive women. Howard is called by the FBI. (S4 Ep7) [AD,S]
The 21-Second Excitation: The gang's plans to attend a film screening are scuppered by Sheldon's nemesis Wil Wheaton. Penny and Bernadette invite Amy to her first slumber party. (S4 Ep8) [AD,S]
The Boyfriend Complexity: When Penny's father visits, Leonard discovers that her parents still think that he and Penny are a couple, so he takes advantage of the situation. (S4 Ep9) [AD,S]
The Laureate Accumulation: When their academic competitors charm America on a publicity tour, Sheldon and Amy try to get some Nobel laureates on their side. (S12 Ep18) [AD,S]
The Inspiration Deprivation: Amy has a meltdown when she feels the pressure of what it would mean for women everywhere if she were to win a Nobel Prize. (S12 Ep19) [AD,S]
The Laureate Accumulation: When their academic competitors charm America on a publicity tour, Sheldon and Amy try to get some Nobel laureates on their side. (S12 Ep18) [AD,S]
The Inspiration Deprivation: Amy has a meltdown when she feels the pressure of what it would mean for women everywhere if she were to win a Nobel Prize. (S12 Ep19) [AD,S]
The Bitcoin Entanglement: Sheldon seeks revenge when the guys cut him out of a potentially valuable investment. A secret about Leonard and Penny is revealed. (S11 Ep9) [AD,S]
The Celebration Reverberation: Sheldon and Howard plan birthday celebrations for Amy and Halley. Leonard is stressed by a Christmas letter from his brother. (S11 Ep11) [AD,S]
The Bitcoin Entanglement: Sheldon seeks revenge when the guys cut him out of a potentially valuable investment. A secret about Leonard and Penny is revealed. (S11 Ep9) [AD,S]
The Matrimonial Metric: Sheldon and Amy secretly test their friends, to work out who should be best man and maid of honour at their wedding. (S11 Ep12) [AD,S]
The Celebration Reverberation: Sheldon and Howard plan birthday celebrations for Amy and Halley. Leonard is stressed by a Christmas letter from his brother. (S11 Ep11) [AD,S]
The Matrimonial Metric: Sheldon and Amy secretly test their friends, to work out who should be best man and maid of honour at their wedding. (S11 Ep12) [AD,S]
The Change Constant: Sheldon and Amy stay up late awaiting a phone call that could bring big news from the Nobel Committee: are their lives about to change? (S12 Ep23) [AD,S]
The Stockholm Syndrome: Howard and Bernadette go on a trip without their children, Leonard and Penny try to keep a secret, and Raj makes a new friend. (S12 Ep24) [AD,S]
The Change Constant: Sheldon and Amy stay up late awaiting a phone call that could bring big news from the Nobel Committee: are their lives about to change? (S12 Ep23) [AD,S]
The Stockholm Syndrome: Howard and Bernadette go on a trip without their children, Leonard and Penny try to keep a secret, and Raj makes a new friend. (S12 Ep24) [AD,S]
The Commitment Determination: Sheldon pressures Leonard and Penny to choose a date for their wedding while dealing with changes in his own relationship. (S8 Ep24) [AD,S]
The Maternal Combustion: Personalities collide when Sheldon and Leonard's mothers finally meet. Howard decides to 'man up' and do his share of the housework. (S8 Ep23) [AD,S]
The Graduation Transmission: Leonard is invited to make a speech at his old high school. Howard and Sheldon can't make a toy drone fly. (S8 Ep22) [AD,S]
The Communication Deterioration: Raj is asked to create a message for NASA to use if one of their missions finds alien life. Penny considers taking up acting again. (S8 Ep21) [AD,S]
The Fortification Implementation: When Sheldon and Amy build a blanket fort, they come to a major crossroads in their relationship. Howard meets his half-brother. (S8 Ep20) [AD,S]
The Skywalker Incursion: When Leonard and Sheldon are invited to speak at Berkeley, they take a detour during the journey to try to meet one of their idols. (S8 Ep19) [AD,S]
The Leftover Thermalization: A power cut at Mrs Wolowitz's house defrosts the last meal she prepared before her death, so the gang consume it in her honour. (S8 Ep18) [AD,S]
The Colonization Application: Amy learns that Sheldon has applied to take part in a one-way mission to colonise Mars. Leonard surprises Penny with a gift. (S8 Ep17) [AD,S]
The Intimacy Acceleration: When the gang hear about an experiment designed to make participants fall in love, Sheldon and Penny put it to the test as a joke. (S8 Ep16) [AD,S]
The Comic Book Store Regeneration: The gang prepare for the reopening of Stuart's comic book shop. Penny teaches Sheldon to 'let it go' when he is irritated. (S8 Ep15) [AD,S]
The Troll Manifestation: Leonard and Sheldon co-publish a physics paper but are forced to defend themselves against negative comments from an online critic. (S8 Ep14) [AD,S]
The Anxiety Optimization: When Sheldon gets stuck in a rut with his research, he asks his friends to cure his mental block by raising his stress levels. (S8 Ep13) [AD,S]
The Space Probe Disintegration: Howard tries to calm a stressed Raj, who is anxiously awaiting the arrival of some data from a space probe that he helped launch. (S8 Ep12) [AD,S]
The Clean Room Infiltration: Amy hosts a Victorian Christmas Eve dinner, complete with party games. Raj, Leonard and Howard have pigeon problems. (S8 Ep11) [AD,S]
The Champagne Reflection: Sheldon and Amy record the final episode of their internet show Fun with Flags. Penny tells Bernadette how her colleagues really feel about her. (S8 Ep10) [AD,S]
The Septum Deviation: When Leonard has to have minor surgery on his nose, Sheldon is the one who seems to need sympathy. Raj is upset when his parents split up. (S8 Ep9) [AD,S]
The Prom Equivalency: The girls decide to re-enact their high school proms with their current partners on the roof of the apartment building. (S8 Ep8) [AD,S]
The Misinterpretation Agitation: A smitten doctor turns up at Penny's door after her flirtatious sales techniques for the pharmaceutical company work a little too well. (S8 Ep7) [AD,S]
The Expedition Approximation: Sheldon and Raj try to find out if they could survive a dark-matter research expedition in a salt mine by simulating the conditions in a tunnel. (S8 Ep6) [AD,S]
The Focus Attenuation: The guys attempt to invent something of scientific importance but only come up with new and enjoyable ways to procrastinate. (S8 Ep5) [AD,S]
The Hook-Up Reverberation: Raj's honesty about his past comes back to haunt him when his girlfriend Emily gives Penny the cold shoulder. The guys consider an investment. (S8 Ep4) [AD,S]
The First Pitch Insufficiency: Howard's nervous when NASA ask him to throw the first pitch at a baseball game. Sheldon claims his and Amy's relationship is the best in the gang. (S8 Ep3) [AD,S]
The Junior Professor Solution: When Sheldon has to teach a course at the university, Howard enrols in his class. Tension brews between Penny and Bernadette. (S8 Ep2) [AD,S]
The Locomotion Interruption: Leonard and Amy take an impromptu road trip to Arizona to pick up Sheldon when his epic railway journey ends in chaos. Penny has an interview. (S8 Ep1) [AD,S]
The Deception Verification: Leonard returns early from his research expedition as a surprise for Penny, but Sheldon becomes upset that he wasn't in on the secret. (S7 Ep2) [AD,S]
The Hofstadter Insufficiency: Sheldon and Penny bond while Leonard is away. Raj finds someone to share his heartache. Bernadette and Amy attract male attention at a conference. (S7 Ep1) [AD,S]
The Status Quo Combustion: With potential changes affecting different aspects of his personal and professional life, Sheldon is forced to confront an uncertain future. (S7 Ep24) [AD,S]
The Gorilla Dissolution: Penny re-evaluates her life, including taking a big step with Leonard, while Howard and Bernadette struggle to look after Mrs Wolowitz. (S7 Ep23) [AD,S]
The Proton Transmogrification: Sheldon struggles to process his feelings of grief when his idol Professor Proton passes away. The gang gather to celebrate Star Wars Day. (S7 Ep22) [AD,S]
The Anything Can Happen Recurrence: Penny and Leonard distract Sheldon from his career problems by reinstating Anything Can Happen Thursday. Raj asks for Howard's advice. (S7 Ep21) [AD,S]
The Relationship Diremption: Sheldon wonders whether he's wasting his time with his study of string theory. Raj and Emily go on a double date with Howard and Bernadette. (S7 Ep20) [AD,S]
The Indecision Amalgamation: Raj has a dating dilemma. Penny can't decide whether to accept a role in a terrible film. Sheldon chooses between two gaming systems. (S7 Ep19) [AD,S]
The Mommy Observation: Sheldon pays a surprise visit to his mother in Houston and is forced to confront a new reality. Raj throws a murder mystery-themed dinner party. (S7 Ep18) [AD,S]
The Friendship Turbulence: In an attempt to improve their strained friendship, Howard invites Sheldon to visit NASA with him. Penny is upset when her car breaks down. (S7 Ep17) [AD,S]
The Table Polarization: Leonard buys a dining table for the flat but Sheldon objects to such a big change inside his home. Meanwhile, Howard gets the chance to return to space. (S7 Ep16) [AD,S]
The Locomotive Manipulation: Love is in the air when Amy convinces Sheldon to join her for a romantic train trip to Napa Valley to celebrate Valentine's Day. (S7 Ep15) [AD,S]
The Convention Conundrum: After the guys miss out on Comic-Con tickets, Sheldon decides to hold his own comic book convention. The girls take tea at a swanky hotel. (S7 Ep14) [AD,S]
The Occupation Recalibration: Penny quits her job at the restaurant to pursue her acting career full-time. Bernadette accidentally destroys one of Howard's comics. (S7 Ep13) [AD,S]
The Hesitation Ramification: Penny's big TV acting break hits the cutting-room floor, so Leonard does his best to comfort her, which leads her to ask him a bold question. (S7 Ep12) [AD,S]
The Cooper Extraction: Sheldon has to go back to Texas when his sister goes into labour. While he's away, the gang gather at the flat to decorate the Christmas tree. (S7 Ep11) [AD,S]
The Discovery Dissipation: Sheldon feels guilty when he gets attention for his accidental discovery of a new element. Raj stays with Howard and Bernadette for a week. (S7 Ep10) [AD,S]
The Thanksgiving Decoupling: Howard takes the gang to his mother's house for Thanksgiving to protect himself from his grumpy father-in-law who has also been invited. (S7 Ep9) [AD,S]
The Itchy Brain Simulation: Leonard worries that Sheldon will overreact when he confesses that he failed to return a DVD to the rental shop seven years earlier. (S7 Ep8) [AD,S]
The Proton Displacement: Sheldon is jealous when Professor Proton asks Leonard to read his latest publication, so he befriends a TV personality from a rival science show. (S7 Ep7) [AD,S]
The Romance Resonance: Sheldon is mortified when he stumbles upon an important scientific breakthrough by accident. Howard makes a romantic gesture to Bernadette. (S7 Ep6) [AD,S]
The Workplace Proximity: Amy tells Sheldon she's been asked to work on a project at his university, but the guys insist that it will be bad for their relationship. (S7 Ep5) [AD,S]
The Raiders Minimization: Amy ruins one of Sheldon's favourite films by pointing out a flaw in the storyline. Raj and Stuart decide to create online dating profiles. (S7 Ep4) [AD,S]
The Scavenger Vortex: Raj organises an epic and demanding scavenger hunt, designed to test the friends' scientific knowledge and common sense. (S7 Ep3) [AD,S]
The Deception Verification: Leonard returns early from his research expedition as a surprise for Penny, but Sheldon becomes upset that he wasn't in on the secret. (S7 Ep2) [AD,S]
The Decoupling Fluctuation: Sheldon intervenes when he learns that Penny is thinking about breaking up with Leonard, but he's hampered by his inability to keep a secret. (S6 Ep2) [AD,S]