Mark Cendrowski

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…

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…

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,…

Jerrod moves in with his girlfriend, yet he’s reluctant to tell his opinionated parents about the new living arrangement.

While eating at a new cafe with Deacon, Doug manages to agitate their waitress so much that she demands they fight once her shift ends. Meanwhile, Carrie asks Holly to…

Leonard volunteers to sign for a package in an attempt to make a good impression on Penny, but when he enlists Sheldon for help, his attempt at chivalry goes terribly…

Leonard asks a woman out after he finds out that Penny is seeing someone.

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.

Penny hosts a Halloween party, putting Leonard, Sheldon, Wolowitz, and Koothrappali through a new test of their social skills.

With Wolowitz AWOL with one of her friends, Penny’s recruited to fill in for him on the guys’ Halo team

Leonard and Sheldon each lie to avoid seeing Penny’s concert, but Sheldon’s is a bit too complicated for his own good.

With his friends knowing how sour he acts when sick—and avoiding him as a result—Sheldon is nursed by Penny, who hasn’t a clue what she’s in for.

With Sheldon rattled over meeting Dennis, a 15-year-old physicist who’s smarter than he, Leonard helps him look for a way to debunk Dennis’s research.

Sheldon finds himself booted from the gang’s Physics Bowl team and replaced with Leslie, so he forms his own team, hoping to prove he’s superior.

When delivery of another collectible leads to Penny’s lashing out at Leonard, he decides it’s time to give up his habit, much to his friends’ protestation.

The rest of the gang fall for Sheldon’s twin sister, and Leonard’s plan to win her heart is derailed when Sheldon declares he’ll be the one to decide who can…

Penny wants to throw a surprise party for Leonard, but Sheldon’s indulgence at an electronics store throws her off-track.

Penny’s break-up spurs Leonard to summon the courage to ask her out, and each goes to Sheldon for advice on their upcoming date.

Penny’s first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.

A jealous Leonard reacts to Penny’s new guy by rebounding with Leslie.

Sheldon creates a monster when he introduces Penny to online gaming.

Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.

Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.

Sheldon and the gang are confused when a young grad student is attracted to him.

When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.

Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.

Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon’s stringent standards.

Leonard asks Penny for advice when his new relationship starts moving too fast.

Penny starts dating Leonard’s handsome colleague; Leonard and his friends are tortured by Sheldon’s obsession with gift-giving etiquette.

Penny’s criticism of Wolowitz’s romantic life pushes him into depression and AWOL for a fighting robot battle the rest of guys are depending on him for.

Sheldon creates a scientific procedure for making friends.

Sheldon’s solution to Penny’s financial difficulty leads to a confrontation between Leonard and Penny’s ex-boyfriend.

Leonard and Penny are drawn together after a disastrous visit from Leonard’s mother.

A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.

Leonard, Sheldon and Wolowitz are ecstatic to learn that a famous science-fiction actress (Summer Glau) is on board the train they are taking to San Francisco.

Penny squares off with a new beautiful female neighbor who may become the building’s ”new Penny.”

A fellow comic book enthusiast’s hitting on Penny leads to Leonard and Howard going to a bar’s Ladies’ Night.

Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.

Penny’s second date with Stuart sees her making a comment that gives Leonard new hope for a relationship with her. Wolowitz realizes there’s a crucial error in a NASA project…

The guys’ plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.

When Sheldon learns the guys tampered with his expedition data he got from the arctic, he leaves to Texas in disgrace. This results in the guys following him, which threatens…

Leonard and Penny struggle to recover from an awkward first hookup while Sheldon and Howard stake their best comic books on a bet to determine the species of a cricket.

Howard and Raj visit a Goth nightclub to pick up women while Sheldon attempts to build a better Penny using chocolate-based behavior modification.

Raj must find a new job or be sent back to India, but Sheldon has a solution, which leaves Leonard and Penny dealing with Howard as a third wheel.

After overhearing that Wil Wheaton is entering a trading-card competition, Sheldon decides to enter it himself. Meanwhile, Penny sets up one of her friends on a date with Wolowitz.

Sheldon becomes Leonard’s teacher in order to understand football, while an incident with flying a kite threatens Howard and Raj’s friendship.

A squabble between Leonard and Penny sees Sheldon playing mediator, though out of his own incovenience from the sitiation rather than altruism.

With Leonard, Howard and Raj away camping in the desert, an injured Penny has only Sheldon to rely on.

After he’s humiliated on National Public Radio, Sheldon vows to destroy Kripke, while Wolowitz tries not to destroy his new relationship with Bernadette.

Penny gets help from Sheldon in order to understand what Leonard’s work is, while Wolowitz develops a jealousy when Leonard starts hanging out with his new girlfriend.

A Christmas visit from his mother has Leonard discovering she’s kept a lot of news from him that she shares with Sheldon and worrying if she’ll approve of his romance…

Leonard is aghast to find out a secret of Penny’s: she believes in psychics. Meanwhile, Sheldon tries to assist Koothrappali in picking up a girl at a university mixer.

When their apartment is robbed, Leonard and Sheldon turn to their friends to create a state-of-the-art security system.

Sheldon’s search for the answer to a physics problem leads him to work at the Cheesecake Factory with Penny.

Leonard can only bring one guest on a trip to see CERN’s Large Hadron Collider (the world’s largest and highest energy particle accelerator) in Switzerland on Valentine’s Day.

When the guys find a ring from ”The Lord of the Rings” at a garage sale, it threatens to tear them apart.

Sheldon’s friends come to his aid when his fear of public speaking stands between him and a coveted award.

A fight between Leonard and Penny threatens their relationship, while Sheldon battles Wil Wheaton in bowling.

Leonard and Sheldon compete for the attention of a famous female physicist.

Leonard tells Penny about how he met Sheldon for the first time…and what happened to the elevator.

Penny tags along on Sheldon’s first ever date; Wolowitz finds a new use for a robotic arm.

Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.

The guys are concerned as Sheldon searches for an alternative to human companionship.

An embarrassing secret of Wolowitz’s comes to light, while Sheldon and Raj have a small war at work.

Leonard realizes he’s the only one without a girlfriend, while Sheldon wants to get rid of his.

Leonard keeps an affair a secret from Sheldon, Howard and Raj.

Sheldon’s answers during an FBI interview put Wolowitz’s security clearance in jeopardy.

While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.

Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.

Amy finds she has sexual feelings for Penny’s ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.

The guys find a ”super” use for Penny’s new boyfriend, Zack, when they enter a costume contest as the Justice League.

Leonard’s idea for a smartphone app derails his friendship with Sheldon.

Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend’s girlfriend.

A wealthy donor to the university makes Leonard consider how far he’s willing to go for the sake of science.

As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj’s sister.

Sheldon becomes concerned when everybody begins to hang out at Raj’s apartment and discovers Leonard is the center of the group.

Sheldon is baffled by Wolowitz’s magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.

Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to even higher level.

When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violations of the roommate agreement. However, before he can get too far, Priya uses…

Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.

When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she’s regrets.

Penny is worried with how damaged her friendship with the guys will be in the aftermath of her sleeping with Raj while Sheldon becomes the leader of the paintball team.

A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up his long-distance relationship with Priya.

Leonard and Amy get to know each other better, while Howard and Bernadette spend the weekend with Mrs. Wolowitz.

Penny plays Matchmaker for Raj, which results in him finding a girl he is comfortable talking to.

Sheldon and Leonard get invited to a party at Wil Wheaton’s house, and Howard gets an out-of-this-world opportunity.

A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to scare the guys for Halloween.

Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping without her.

Leonard and Penny try hanging out as friends on a ’non-date’, but end up purposely ruining each others chances with perspective dates. Meanwhile, Sheldon enlists the help of Bernadette and…

When Stuart asks Amy out on a date, Sheldon must confront his feelings and consider where his relationship with Amy is going.

Sheldon gets in trouble with Amy when he isn’t impressed by her recent accomplishment, and Howard must come to grips with Bernadette’s dislike of children.

Leonard, who broke up with Priya, asks Penny out to a spur-of the-moment romantic dinner for two, and the duo contemplates on their relationship.

Leonard and Penny deal with the idea of starting a relationship again and Raj finally finds a ”woman” he can talk to without being drunk, in the form of Siri…

Sheldon’s selfish demands force Leonard to reconsider their friendship. Meanwhile, Wolowitz tries to pick his astronaut nickname.

When Sheldon is forced to take his vacation, he goes to work with Amy in her neurobiology lab.