Sheldon is concerned that he isn’t making fast enough progress on his new field of Dark Matter because he is constantly being distracted, so he has purchased a new set of noise-cancelling headphones. As Leonard and Penny are about to go out on a date, he asks them to help him test them. After Sheldon dons the headsets, Leonard makes an innocuous statement and when he gets no response, he and Penny begin to taunt 
Sheldon by telling him things that would normally drive him crazy. Mid-sentence, as Sheldon removes the headsets, Leonard switches to saying, “and that’s why you’re the best roommate ever,” leading Sheldon to state that he wishes he could have heard the whole thing, despite his acknowledgement as recently as the previous episode when he admitted that he could be a difficult roommate. Of course, we have also learned that Sheldon’s concentration is not particularly long-lasting. By the time Leonard and Penny return, Sheldon has only succeeded in repeating “Proton decay” over and over.
The next day, Sheldon has decided not to go into work due to his failure to have any success in his new field of study. Rather than argue with him, Leonard heads out to work, quickly followed by Sheldon, who has decided he needs the fresh air of the hallway. While taking deep breaths of hallway air, he hears strange noises coming from Penny’s apartment. Deciding she must be in distress, he rushes to her door for his traditional triple knock. He bursts in on an exercising Penny who couldn’t hear the knocking because she was wearing earbuds. Sheldon explains he thought she was either being murdered or having sex, sorry, coitus, with Leonard. Sheldon doesn’t understand Penny’s exercising despite hating it.
In the cafeteria, Howard invites Leonard to play a game he’s calling “Emily or Cinnamon,” the objective being to identify whether Raj was speaking to his girlfriend or his dog when he made such comments as “I want you to know the bed feels so lonely when you’re not in it” and “You know a man can care deeply about a woman and a pet, you know it’s not strange.” Raj is not as amused by the quotes as the others are. They are joined by a Sheldon, who has decided to come into work after all, pointing out to Leonard that Penny is trying much harder to stay attractive than Leonard is. More importantly, he’s decided that his environment is too pleasant, citing the research of Robert Yerkes and John Dodson. Given how outspoken Sheldon has been about psychology and sociology, he seems to be quite aware of research in those fields, given this reference and his discussions of psychology earlier this season I “The First Pitch Insufficiency.” In any event, he asks the others to annoy him. When they realize it is the chance to make Sheldon miserable, all three jump at the chance.
Having a neurologist as a girlfriend means that Sheldon can be scientific about trying to figure out what he needs to do to maximize his (theoretical) productivity. Amy has hooked him up to a biofeedback machine and a Snoopy hat. As he finishes a test, Amy announces that they’ve found his baseline, leading Sheldon to complain that if he were a mouse, he would have received a treat. When Amy points out the mouse also would have his brains scooped out, Sheldon is less keen on the idea of a treat. Amy begins to test how anxiety impacts Sheldon’s problem solving abilities by playing with a balloon near him until he removes the annoyance. As Sheldon begins to think it is a waste of time, Amy finds his peak level of annoyance.
Back in the apartment it is game night and Raj brings a bunch of games to play, but Howard is stuck on “Emily or Cinnamon,” dismissing Raj’s suggestion that Howard is jealous of Raj’s relationship with Emily. Sheldon enters and asks the three to become his intellectual sparring partners to allow him to maintain a level of annoyance and also see other points of view (not that he would). This leads to a scene reminiscent of the Monty Python sketch “Argument Clinic.”
In Penny’s apartment, she is telling Bernadette and Amy that the rep with the best sales for the quarter will win a trip to Hawaii. When Amy comments on how romantic that would be, Penny points out that Leonard on a beach with a metal detector is more geeky than romantic. Amy responds by raving about the Keck Observatory and how she would spend all her time there, leading Penny to invite Bernadette to be her plus one if she wins the trip. Sheldon bursts in to raise his anxiety levels by listening to the women talk, demonstrating strongly his misogynistic which so frequently gets ignored, although this time Penny calls him on it. Penny points out that they talk about the same thing the guys talk about (patently untrue since they don’t talk about comics and Geek culture when the guys aren’t around).
Back in his apartment while Leonard is trying to sleep, Sheldon is working while wearing his Snoopy hat and listening to a mash up of the Joker, Godzilla, and Darth Vader to keep his anxiety (and his roommate) up. Since his white board is covered in equations, it seems to be working. He is then shown at date night with Amy, still in his Snoopy hat, and still working, claiming he can multitask and demonstrating that he can’t. Amy complains that he needs to take off the cap and stop focusing so much on work. When Howard refuses, he finds himself on a bus hallucinating an armadillo-human next to him.
While Amy and Sheldon are on a date at Amy’s apartment, the Wolowitzes are having dinner with Penny and Leonard, and playing a game of “Emily or Cinnamon” with a split vote and Penny having to decide who the sentence was said to. As she guesses correctly, Raj enters the apartment and they promise to stop since, as Raj points out, it would hurt her feelings if she learned about the game, leading Bernadette to ask if he was referring to Emily or Cinnamon.
When Sheldon gets back to the apartment, Penny and Sheldon try to put Sheldon to bed. Although Sheldon fights sleep, when Penny and Leonard start singing “Soft Kitty” to him, he’s too tired to argue that it should only be used when someone is sick, and he allows himself to fall asleep. As they look at the calm, sleeping Sheldon, the consider how easy it would be to hold a pillow over his face, in a call back to last season’s “The Itchy Brain Simulation” in which Penny pointed out to Leonard that any night that Leonard didn’t kill Sheldon, Sheldon won.
In the kicker, Howard, Leonard, and Sheldon are eating when Raj and Emily (in one of her rare actual appearances) join them. Emily has heard about the game and informs them that she thinks Raj’s sensitivity makes him sweet and sexy, although she does question why there’s dog hair in his mouth when she kisses him, leading to the question of how she can tell dog hair from human hair.
While Sheldon and Bernadette attempt to use science to resolve Sheldon’s dilemma, Raj brings in the geek culture factor with his suggestion (not spoken, but shown) that they play Ticket to Ride, which, of course, is rejected in favor of a rousing game of “Emily or Cinnamon.”
