When Howard dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny’s Halloween party; Meanwhile, Leonard is shocked that Penny doesn't remember their first kiss.
While Raj is worried that people won’t take him seriously in his own field after publishing a paper suggesting he may have discovered alien life, Penny encourages Leonard to stand up for himself when he wants to be the principal investigator on a plasma physics study.
The game is afoot when Glenn declares that all employees will receive a $200 bonus if the store reaches a certain sales goal by the end of the day. As the associates scramble to upsell their customers, Jonah struggles with his morality until he gives in and convinces a customer to purchase many expensive items...Who happens to be Amy's husband! Meanwhile, a bored Glenn and Dina work together to throw a party for everyone after they meet their sales goals.
When Sheldon is no longer academically challenged at Medford High, he audits a college class taught by a professor (special guest star WALLACE SHAWN).
Katie's holiday spirit is soured when Viv corners her into helping out with the school Christmas pageant. Greg, determined to teach Taylor and Oliver the true meaning of Christmas, takes them to a local nursing home to cheer up the residents.
