In the Season 6 finale, Penny is thrown for a loop when Leonard is offered a job overseas, but the news is an even bigger shock to Sheldon. Raj wants more out of his relationship with Lucy than she can handle.
When Sheldon is required by the Relationship Agreement to take Amy out for their second anniversary, he asks Raj to tag along. Leonard has difficulty being with Penny and not asking where their relationship is heading.
The gang wants Penny to tell Leonard how she feels about him. Howard is the target of practical jokes on the space station. Raj and Stuart plan to go out on the town.
When Sheldon hires a female grad student to assist him, a jealous Amy asks Penny to help her spy on them, only to make a shocking discovery. Life in the International Space Station is wearing on Howard.
Howard is offended when his return from space is met with little fanfare but he gets an even bigger surprise at home. Game Night turns into a battle royale between Penny and Sheldon.
Wolowitz must make a decision whether or not to move out of his mother's house, and Sheldon is caught in the middle of an argument between Amy and Wil Wheaton.
Howard tries to bond with Bernadette's father during a fishing trip. When Sheldon is obligated to take care of a sick Amy, she finds ways to take advantage of the situation.
Penny finds out that Sheldon's assistant is hitting on Leonard, and Sheldon gets himself and his friends in trouble with Human Resources trying to solve the problem.
The guys are stranded in the middle of nowhere when Leonard's car is stolen on the way to the Bakersfield Comic-Con. Back home, the women try to figure out why the guys are so fascinated with comic books.
Sheldon is forced to work with Barry Kripke on a project and must concoct an elaborate lie when he can't hold up his end of the work. Howard and Raj get superhero figurines made of themselves.
Leonard moves in with Penny after a fight with Sheldon, which causes Amy to want to move in with Sheldon. Meanwhile, Raj has a frightening experience with Howard's mom.
Sheldon tasks his assistant to buy a Valentine's Day gift for Amy. Leonard, Penny, Howard, and Bernadette have a disastrous dinner together, while Raj and Stuart host a "Lonely People" party at the comic book store.
Raj falls apart after his date sneaks out on him, and Sheldon reluctantly returns the favor after Penny helps him out with his "Fun With Flags" program.
Raj devises a date for Lucy that fixes their social anxiety problems. Leonard, Sheldon, and Howard give lectures on science to junior high students. Penny, Amy, and Bernadette ditch work to go to Disneyland.
Bernadette and Howard offer to watch Raj's dog and live to regret it. Leonard and Sheldon hire their favorite childhood star, Professor Proton (Bob Newhart), to make an appearance.
A date between Raj and Lucy takes both of them out of their comfort zones. After a trip to Las Vegas goes awry, the ladies join in on a Dungeons & Dragons game, which causes Amy and Sheldon to reevaluate their relationship.
In the Season 6 finale, Penny is thrown for a loop when Leonard is offered a job overseas, but the news is an even bigger shock to Sheldon. Raj wants more out of his relationship with Lucy than she can handle.