The Wiggly Finger Catalyst

Sheldon, Leonard, Howard and Raj are playing a game of Dungeons & Dragons, but Leonard becomes concerned when Raj eats a whole pie and states he has no reason to watch his figure as he is not in a relationship. Across the hall, Penny, Bernadette and Amy are also discussing Raj's loneliness. Penny introduces Raj to her deaf friend Emily. Though Raj's selective mutism is not an issue, Penny calls Howard to interpret Emily's sign language to Raj. The two go out on a date at a coffee shop, and with Howard's help, the date goes reasonably well.

One month later, Howard reveals that Raj is buying Emily many expensive gifts, with Sheldon saying he can do so as his family is rich. Concerned that Emily is exploiting Raj for his wealth, Penny and Howard confront her at her gym. Howard gets distracted by the women there and asks Emily straight up if she is a gold digger, causing an angry Emily to swear at them and storm off. Raj, angry over the ambush, confronts Penny and accuses her of being jealous ever since they slept together.

Determined to break the two up, Penny calls Raj's parents and informs them of the situation. They threaten to cut him off if he continues to date her. A defiant Raj refuses to break up with Emily, but once she discovers he is no longer rich and that he has to return the gifts he bought her, she dumps him. The guys then go to the Cheesecake Factory and make Raj pay for everyone's meal, with Penny telling him not to "cheap out" on the tip, since they now know he is rich.

Meanwhile, Sheldon uses Dungeons & Dragons dice to make trivial decisions, such as what to order in a restaurant, so his mind can focus more on his work. Although he manages to co-author two papers and make considerable progress towards explaining why the Large Hadron Collider has not yet isolated the Higgs boson particle, he grows a ridiculous-looking mustache, gets chafed testicles from not wearing underwear and has to wait to use the restroom when he needs to urinate.