Leonard gets a new job opportunity to work abroad for the summer and Sheldon is feeling a little bit jealous. Meanwhile, Raj tries to move his relationship with Lucy into a new direction by introducing her to his friends, but he fears that she may not like them.
After an aborted girls' trip to Vegas, they are all playing Dungeons and Dragons together. Raj leaves after he finds that Lucy is free and he pushes her to do things that scare her. In the game, Penny casts a love spell on Sheldon and Amy's characters which gets Amy very upset because they are treating her and Sheldon's relationship as a joke.moreless
When Sheldon and Leonard learn their favorite TV scientist is available to hire, they seek to do so. Howard and Bernadette are tasked with watching Raj's dog.
Sheldon feels lost after one of his favorite TV shows gets canceled too soon and Amy tries to help him get over his compulsive need for closure. Meanwhile, Raj discovers a secret about his new love interest, Lucy.
Competition between the guys increases when a slot for a tenured professor opens up and they start to schmooze the tenure committee members that include Mrs. Davies from Human Resources who Sheldon has crossed paths with before.
Bernadette prepares a dinner for the gang, however Sheldon brings his own Thai take-out food after she makes Sheldon's Thai food from scratch. Sheldon rearranges Howard and Bernadette's closet and finds an unopened letter from Howard's father, sent for his 18th birthday. Penny and Leonard decide to invite the gang for a formal dinner party.moreless
Raj and Lucy have their first date meeting in a library and texting to each other. The guys have to promote science careers for women at Howard's old middle school, while the girls go to Disneyland and get made up as Disney Princesses.
Sheldon has Penny as a guest on a "Fun with Flags" episode and she gets him to attend her acting class' presentation of "A Streetcar Named Desire". Raj drops out after Lucy unexpectedly leaves their first get together.
The couples are getting for Valentines' Day. Leonard, Penny, Howard and Bernadette are going to dinner. Sheldon and Amy are trying to get the perfect gifts for each other. Raj and Stuart are planning a singles only party at The Comic Book Store.
With Leonard mad at Sheldon, he moves in with Penny. Amy notes that she would be the perfect roommate for Sheldon since she knows him so well and he wouldn't have to break in someone else. Sheldon and Penny are not happy with these arrangements. Raj is trapped in the Wolowitz house with Howard's lonely mother.moreless
Sheldon is forced to work with Kripke and while in competition with Kripke, ends up spreading rumors about his sexual relationship with Amy. Howard and Raj get action figures of themselves that cost $1000.
Sheldon gets all the guys before the Human Resources Department when he tries to talk to Alex about her advances to Leonard. Alex's actions also make Penny feel insecure.
Guys plan to play Dungeons and Dragons, but girls are not invited, which causes arguments among them and the girls. After playing for some time at the apartment, the girls show up dressed sexily for a girls' night out and Raj goes with them to the nightclub.
Howard and Bernadette have a tense dinner with both of her parents. The subject of Mr. Rostenkowski's weekend fishing trip comes up and Howard is hooked into going with him. The guys visit Penny to learn all about fishing since she used to go with her dad. Sheldon shows up at Amy's apartment to find his girlfriend sick. After initially rejecting her request, Sheldon stays to take care of Amy the way his mother took care of him, sometimes a bit intimately.moreless
When the University reassigns Sheldon's parking spot to Wolowitz, their fight affects the whole gang.
Raj and Howard try to figure out Sheldon's secret daily afternoon routine. Meanwhile, jealousy takes over Leonard and Penny's relationship.
Sheldon hires an assistant. Amy gets incredibly jealous of Sheldon having a female assistant, but Alex is actually more interested in Leonard. Meanwhile, Wolowitz' return from space has been delayed a week and he starts to lose his mind because of it.
Sheldon once again has to keep a secret when he learns Leonard and Penny are going to break up. Howard keeps getting teased by his fellow astronauts in space.
Wolowitz is caught in an argument between Bernadette and his mom, even while he's in space. Meanwhile, with his friends on dates, Raj feels lonely.