"The Dead Hooker Juxtaposition"

Penny gets jealous of the guys' new sexy female neighbor (Valerie Azlynn)

"The Work Song Nanocluster"

The boys help Penny with her new business selling Penny Blossoms.

"The Terminator Decoupling"

On a train ride to San Francisco, Leonard, Sheldon, Wolowitz, and Raj discover that Summer Glau is on their train ride.

"The Cushion Saturation"

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

"The Maternal Capacitance"

Leonard's mother, Mrs. Hofstadter (Christine Branksi) comes into town and she ends up being exactly like Sheldon.

"The Financial Permeability"

Sheldon lends Penny some money which makes Leonard go and try and collect some money from her ex-boyfriend Kurt for her.

"The Friendship Algorithm"

In order to get time on the super computer at work that he needs for his experiment, Sheldon must befriend Kripke who is in charge of the device.

"The Killer Robot Instability"

When Penny's comments about Wolowitz's love life sends him into depression, the boys are about to lose their most important teammate in an upcoming robot fighting competition.

"The Bath Item Gift Hypothesis"

It's Christmas time and Sheldon is annoying everyone with his theories on gift giving etiquette. Meanwhile, Leonard gets jealous when Penny stars dating one of his handsome co-workers.

"The Vartabedian Conundrum"

When Sheldon and Penny convince Leonard that Stephanie has moved in, Sheldon tries to slow the relationship down.

TBBT Quotes

Penny: Here's a question-- as an alien pretending to be human, are you planning to engage in any post-prom mating rituals with Amy?
Sheldon: There are post-prom mating rituals?
Penny: Not always. Unless your date drives a van with an air mattress, then always.
Sheldon: Well, if it's part of the prom experience, then I'm open to it.
Penny: You're kidding.
Sheldon: I may be an alien, but I have urges.If Amy wants to copulate by firing her eggs into space, well, then, I will happily catch them with the reproductive sac on my upper flermin. I'm not the best at reading facial cues, but I can see that you're a little turned on.

Sheldon: If you could wake up tomorrow having gained any one quality or ability, what would it be?
Penny: Well, not to steal from the Bible, but turning water into wine sounds pretty good.