Avery's sister has been kidnapped and ransomed for $2,000,000. Desperate, he and his buddies abduct a retired mob boss to try to force him to use his contacts to find the girl.

Two roommates, both genius physicists, live in their own world with their friends until an attractive woman moves in across the hall and helps them see life in different ways.

The Leonard and Penny went from next-door neighbors to next-door newlyweds with a nuptial excursion to Vegas. This season, they find themselves in a repeating paradigm as they re-create their wedding, this time with family including Penny's mother and brother and Leonard's parents. Meanwhile, the Relationship Agreement between Sheldon and Amy added an entirely new subsection with their annual coitus clause.

This season the Big Bang gang's romantic universe expands. On the rebound from Penny, Leonard falls into the arms of Raj's sister Priya. Sheldon gets a girlfriend, or rather a friend who is a girl: Amy, a dour neurobiologist who declares herself besties with Penny. Howard and Bernadette heat up. And so do Raj and Bernadette (at least in Raj's Bollywood daydream). All in the furtherance of award-winning genius comedy.

It's Christmas time and Clark decides to invite all the family to have 'the most fun-filled old-fashioned family Christmas, that no one will ever forget.' When the first relatives arrive, Clark goes out on the roof to rig the lighting. The one thing that Clark wants is to surprise the whole family with is the installation of a pool, which he already ordered. Unfortunately, the bonus check Clark expects any minute is overdue. Tempers rise and not just...

Socially challenged they remain, but the scientific geniuses of show always deliver hilarious results. Leonard returns from his North Sea expedition to find that his relationship with Penny involves more beta-testing than he's ever done in a lab. Howard's attachment issues with women in his life in particular and Raj's social breakthrough with women in general provide more laughs. Bernadette and Amy stand staunchly by the men in their life, even when...

Despite their on-again, off-again relationship in the past, Leonard and Penny have finally gotten married. Even Sheldon has found a female companion, entering into a 'relationship agreement' with neurobiologist Amy Farrah Fowler, and he recently took their relationship to the next level by marrying her after a long courtship. Will their equation for marital bliss alter the chemistry between these two beautiful minds? Quantum comedy converges in the...

He's baaack! Sheldon is rescued from his soul-searching cross-country train trip (older but no wiser) and that means the gang's all here to spread another year's cheer as TV's most attended laugh seminar. Enroll in this comic curriculum to explore Leonard's minor surgery becoming a major catastrophe from his roommate, Howard's obsession over his mom's relationship with retailer-turned-caretaker Stuart, and the peculiar results of Penny's technique...

Prepare to enter phase nine of television's perpetual laughter experiment as the show successfully fuses the elements of science and sitcom. Our two genius roommates, Leonard and Sheldon, and their friends are back once again (smarter, but no wiser). Last season, Sheldon went soul-searching (on a train, of course) and was prepared to make some substantial revisions on his Relationship Agreement with Amy, when everything changed.