Sheldon faces a crisis of conscience after breaking a Star Trek toy given to him by Penny. Meanwhile, a lonesome Raj is smitten after a date set up by his parents.
Sheldon is forced into altering his precious schedule after his barber falls ill. Meanwhile, the training required to be an astronaut has Wolowitz wondering if he has the right stuff.
When a new office space is made available, Sheldon goes head to head with his nemesis, Kripke, for the right to move in. Meanwhile, Penny is unsettled by painting given to her by Amy.
Forced to use his vacation time, Sheldon dabbles in biology in Amy's lab. Bernadette reveals to the girls that her father wants her to make Howard sign a pre-nup.
Leonard can't take Sheldon's continued selfishness and agrees to dissolve the Roommate Agreement. Howard wants to have a cool nickname for when he's an astronaut.
Leonard and Penny create lists of 'bugs' in their relationship in an attempt to strengthen it. Meanwhile, Sheldon and Amy create a YouTube video series called Fun with Flags, and Raj develops an unhealthy attachment to Siri on his iPhone.
Sheldon finds himself in hot water when he doesn't appreciate Amy's recent accomplishment. Howard discovers Bernadette doesn't interact well with children.
Sheldon finds himself jealous when Amy goes on a date with Stuart. The other guys can't resist the allure of the latest collectable card game expansion pack.
Sheldon is miffed that Leonard plans to attend a party hosted by his nemesis, Wil Wheaton. Meanwhile, Howard is offered a chance to be a payload specialist on the International Space Station.
Leonard escorts Amy to a wedding. Meanwhile, Howard convinces Bernadette to spend the weekend with him at his mother's house as a trial run, and Sheldon gets involved in model trains.