The Big Bang Theory

After Sheldon's mom & Leonard's dad share an evening together, everyone deals with an awkward morning the next day, on the season premiere.

Colonel Williams, an Air Force representative from the Department of Material Command sits down to talk with Howard.

Tensions rise when the boys struggle to finish their government project on time. Raj learns Bernadette's true feelings about her pregnancy.

When Amy’s apartment floods, she proposes a cohabitation test with Sheldon; Raj learns Howard and Bernadette’s baby’s gender before they do.

Leonard and Penny must separate a quarreling Sheldon and Amy, when their cohabitation experiment doesn't go as planned.

Penny attends Van Nuys Comic Con with Leonard, for her role in Serial Ape-ist. Amy hosts a Sheldon-style brunch at Penny's apartment.

Amy lies to Sheldon about repairs being made to her apartment; Leonard learns that Penny has secretly moved his collectibles into storage.

After an experiment combining their genes, Sheldon is determined to procreate with Amy; Raj is embarrassed with his new date's occupation.

Sheldon is overcome with jealousy when Bert wins a fellowship; Howard finds an old remote control Stephen Hawking action figure he invented.

A battle ensues when Leonard and Sheldon argue over who will get custody of their shared belongings.

While Sheldon and Amy celebrate Amy’s birthday, Howard and Bernadette welcome their new Baby Wolowitz.

Sheldon and Amy visit Leonard and Penny for the first time since the holidays and share details about their terrible trip to Texas.

When Leonard and Penny fight, Sheldon plays the unlikely peacemaker; Howard and Raj try to fix a squeaky floorboard in the baby’s room.

Sheldon beta-tests an MIT invention that can help him read people’s emotions; Raj invites his ex-girlfriends over to give him dating advice.

Leonard & Howard try to distract Sheldon when he slows the progress of their guidance system; Penny & Amy take Bernadette for a night out.

Sheldon and Amy have their first fight since moving in together; Koothrappali is shocked at the realities of financial independence.

When Raj is cut off from his father’s fortune, he appoints Sheldon in charge of his finances; Penny considers joining Leonard at Comic-Con.

When Raj moves out of his apartment, Leonard and Penny offer him Sheldon's old room.

Leonard, Penny and Raj adjust to their new living arrangement, and Sheldon takes an interest in Amy's work.

Sheldon pushes himself to the limit when he collaborates on three projects on the same day; Bernadette nears the end of her maternity leave.

Howard & Bernadette have a hard time leaving Halley in day care when Bernadette returns to work. Bert introduces the gang to his girlfriend.

Leonard isn’t thrilled when Penny considers taking a new job offered by her ex-boyfriend, Zack.

After Leonard, Sheldon and Wolowitz celebrate the completion of the top secret air force project, they are met with an unpleasant surprise.

On the season finale, the gang is concerned when Sheldon’s former admirer, Dr. Ramona Nowitzki resurfaces while Amy is away at Princeton.