On this week’s The Big Bang Theory, Penny invites the gang to a night of wine tasting that she won from work. Everyone is excited, but Bernadette can’t go due to her pregnancy and Sheldon just doesn’t want to go, as it doesn’t sound appealing to him. Sheldon seems to be looking forward to spending Saturday night with Bernadette, while she seems apprehensive.
Raj wants to invite Claire to the wine tasting so everyone can meet her. When Leonard asks about Emily, Raj explains that she is still in the picture but he has an understanding with both girls that they are keeping things casual.
At the wine tasting, Penny runs into her old boyfriend, Zack. She decides not to approach him, but eventually he makes his way over to her. He learns that Penny and Leonard got married and that Leonard and Howard are working on an invention. Zack asks about the invention, trying to sound interested and educated about science. After they tell him about their navigation system, Zack points out that it could be used for weapons.
The guys start to feel worried about their invention, not wanting it to be used to cause destruction. Raj tells them not to let it stop them because almost any scientific advancement can be used for destructive purposes. During their conversation, Claire shows up at the wine tasting and meets everyone.
Eventually, Zack comes back over and makes things awkward when he hits on Claire and talks about how great she is. When Raj takes him aside and asks him to stop making him look bad, Claire asks the gang if Raj brings other girls around. They play it cool and avoid bringing up Emily. When Raj comes back, Claire jokes that they were discussing all of his other girlfriends. Raj gets upset at everyone, saying that he asked them not to tell, accidentally revealing the truth to Claire.
In tonight’s sub-plot, Sheldon has prepared an exciting “fetus-friendly festival of fun” for Bernadette that includes an in-depth look into the world of model trains followed by all of the ways you can make toast. A not-too-excited Bernadette listens as Sheldon tells her about each one of his model trains, including the one he swallowed as a child and had to poop out.
Bernadette asks Sheldon why he likes trains so much. Sheldon explains that trains represented order in his chaotic and confusing childhood. He was able to organize, categorize and control them, giving him a sense of calm.
The evening continues with Sheldon lining up plates of toast prepared in assorted ways. He finishes off with “Star Wars Toast.” One side is burnt, so it has a light side and a dark side.
Next on the agenda is a game of Dungeons and Dragons that Sheldon designed especially for Bernadette. To her surprise, she has fun and thanks Sheldon for a great night. He reminds her that the fun isn’t over, since she will be going home with a goody bag full of toast.