The Big Bang Theory

Sheldon and Penny bond over missing Leonard. Howard tries to help Raj get over his breakup with Lucy. Amy and Bernadette take a trip together to a biology convention.

Sheldon feels betrayed when Leonard returns from the North Sea and wants to spend his time with Penny instead of him. Howard's latest foray into helping his mother has some disastrous side effects.

The gang get competitive when they are forced to take part in Raj's scavenger hunt.

Sheldon gets mad at Amy for ruining one of his favorite movies, Raj and Stuart try to make their online dating profiles more appealing, and Leonard tries to play the sympathy card with Penny.

After a fight with Bernadette, Howard ends up on Raj's couch. Sheldon and Amy clash when Amy takes a job at the university.

Sheldon's trip comes to an end when he is robbed, Penny interviews for a job at Bernadette's company, and Howard is weirded out by his mother's relationship with Stuart.

Sheldon is forced to teach a class as a Junior Professor. Meanwhile, Amy plays both sides when tension arises between Penny and Bernadette.

Howard becomes nervous after NASA asks him to throw out the first pitch at a Los Angeles Angels game. Meanwhile, Leonard and Penny try to prove Sheldon wrong when he says that he and Amy have a 'superior' relationship.

Raj's honesty about his past comes back to haunt him after Emily takes a dislike to Penny. Meanwhile, the guys consider investing in the comic book store.

The girls head to Las Vegas, while the guys try to invent something cool, but only come up with new ways to procrastinate.

Penny struggles with Leonard's confession that he kissed another woman as they prepare to get married in Las Vegas. Meanwhile, Sheldon doesn't know what to do after Amy pushes pause on their relationship.

Leonard and Penny try to work through their marital issues. Meanwhile, Sheldon films a special episode of "Fun with Flags" after his breakup with Amy, and Bernadette feels guilty about withholding a secret from Penny.

The guys's skills are put to the test when they get a flat tire on the way to Mexico for Leonard's bachelor party. The girls throw Penny a mini-bachelorette party.

An impending change to his living arrangements inspires Sheldon to revert to 2003, before he met Penny and Leonard. Raj and Howard form a band for the comic book store.

Kripke expresses interest in Amy while leading a fencing lesson for the guys. Meanwhile, Stuart seeks help from the girls in getting more women interested in the comic book store.

After Leonard's father, Alfred and Sheldon's mother, Mary share an evening together, everyone deals with an awkward morning the following day. Also, Penny's family arrives for the ceremony, including her anxiety-ridden mother, Susan, and her drug dealing brother, Randall.

The Air Force shows interest in the guidance system and Penny lets it slip at work that Bernadette is expecting.

Sheldon can't keep up with the late nights Howard and Leonard are putting in, Raj spends the day with a pregnant Bernadette and Penny and Amy attend a faculty party.

Sheldon helps out when Amy has plumbing problems.

Sheldon and Amy try to work out their cohabitation problems, Howard and Bernadette take a vacation.

Amy gives Sheldon an answer to his proposal while Howard and Bernadette struggle with some unexpected news.

Leonard angers the University and the Physics Community when he gives an embarrassing radio interview. Bernadette and Amy talk about their success. After the embarrassing radio interview Penny comforts her husband.

Sheldon struggles with picking a wedding date. Amy decides she wants a wedding near a cliff which Sheldon doesn't want. Meanwhile Raj and Stuart fight over one of Bernadette's co-workers.

Wolowitz and Sheldon bond when they drive to the desert to shoot off a model rocket. Also, when Leonard's mom finds a new best friend in Penny, it rubs Leonard the wrong way.

Sheldon and Koothrappali confide in Bernadette when they can't handle Amy and Wolowitz working together. Also, Penny and Leonard learn new tactics for how to deal with Sheldon from an unlikely source.

Sheldon and Amy's honeymoon runs aground in New York, while Penny and Leonard discover they are uncomfortably similar to Amy's parents, Mr. and Mrs. Fowler. Also, Koothrappali insults physicist Neil deGrasse Tyson and starts a Twitter war.

Sheldon and Amy drive themselves crazy trying to figure out what “perfect gift” Leonard and Penny gave them for their wedding. Also, Koothrappali decides he wants to settle down and asks his father to arrange a marriage for him.

The Wolowitzes' life gets complicated when Stuart starts bringing his new girlfriend home. Also, Penny and Leonard talk about starting a family while Koothrappali explores an arranged marriage.

When Sheldon won’t tell anyone why he’s never mentioned Tam, his childhood best friend, Leonard takes matters into his own hands. Also, Bernadette and Penny take out Raj’s fiancée, Anu, for dinner to get the skinny on her.

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.