When Sheldon is accused of sexual harassment, he ends up getting Raj, Leonard and Wolowitz in trouble too.
During a game, Sheldon revisits Christmas memories; Amy, Penny and Bernadette look for a date for Koothrappali.
Raj and Howard try to to figure out why Sheldon disappears at 2:45 every afternoon; jealousy arises in Penny and Leonard's relationship.
When Amy gets sick, Sheldon tries to nurse her back to health; Wolowitz and his father-in-law plan a fishing trip.
Bernadette wants Wolowitz to move out of his mom's house; Sheldon is caught in the middle of Amy and Wil Wheaton's argument.
Sheldon and Wolowitz's fight over a parking spot at the University impacts the whole gang.
A game threatens Sheldon's relationship with Stephen Hawking; Penny secretly signs up for a college class.
When Leonard is considered for an exciting research opportunity, Sheldon becomes jealous and tries to scare him into backing out. Meanwhile, Raj's relationship with Lucy is strained when he tries to get her to meet his friends.
The gang heads to Stuart's comic book store to celebrate Halloween; Leonard uses science to seduce Penny.
Amy and Sheldon's relationship takes a surprising turn during a game of "Dungeons & Dragons;" Lucy and Koothrappali have an awkward date.