The Big Bang Theory

Leonard and Amy make an unexpected trip to Arizona to fetch Sheldon; Penny interviews for a job at Bernadette's company;

When Sheldon must teach a class, Howard decides to take it. Amy takes advantage of the tension between Penny and Bernadette.

Wolowitz feels nervous when he is asked to throw the first pitch at a Los Angeles Angels game. Penny and Leonard want to prove

Raj's honesty comes back to haunt him when his new girlfriend is unfriendly to Penny. The guys think about becoming part owners

During their weekend in Las Vegas, Bernadette and Amy accuse Penny of being a buzz kill. The guys try to invent the next big

Sheldon and Raj test whether they could survive a dark-matter research expedition in a salt mine by simulating the conditions in

The guys try to help Penny out of an awkward work dilemma, when a smitten doctor shows up at her door after her flirtatious

When the gang recreates a high-school prom night on the roof of the guys'; apartment building, Sheldon feels pressure to

When Leonard gets minor surgery on his nose, Sheldon is the one in need of sympathy. Meanwhile, Raj's parents' impending divorce

While Sheldon says a tearful goodbye to the final installment of "Fun with Flags", Leonard, Howard and Raj search for something

Leonard and Howard turn to Raj for help in dealing with a work emergency when they nearly come to blows after blaming each other

Wolowitz tries to distract Raj, who is anxiously awaiting data from a space probe he helped launch. Meanwhile, Sheldon and

The gang tries to help Sheldon when he becomes stuck in a rut at work by increasing his anxiety level. Howard teases Raj with a

Leonard and Sheldon publish a paper which is widely accepted except for comments from an internet troll. Meanwhile, the girls

Wolowitz receives some shocking news as everyone prepares for the reopening of Stuart’s comic book store. Penny teaches Sheldon

As a joke, Sheldon and Penny try an experiment designed to make participants fall in love. Also, Leonard, Amy, Raj and Emily

Trouble arises when Amy learns Sheldon has applied for a one-way mission to colonize Mars. Also, a trip to the pet store ends in

Friction ensues when a magazine fails to mention Leonard in an article about the paper he co-wrote with Sheldon. Also, a

When Leonard and Sheldon are invited to speak at UC Berkeley, they take a detour to try to meet an idol. Also, when Bernadette

When Sheldon and Amy build a blanket fort, they come to major crossroads in their relationship. Also, Wolowitz meets the

When Raj is asked to create a message in case a NASA mission discovers alien life, the guys fight over what he should do. Also,

Wolowitz questions his engineering abilities when he and Sheldon can’t get a toy drone to fly. Meanwhile, a cancelled flight

Personalities collide when Sheldon and Leonard’s mothers finally meet. Meanwhile, Howard finally decides to “man up” and do his

Sheldon pushes Leonard and Penny to choose a date for their wedding and deals with dramatic changes in his own relationship with