Plot

Sheldon demands Leonard make up for a mistake from their past. Penny confronts Raj's ex-girlfriend, Lucy.

Out of circumstance, Leonard admits to Sheldon that he still has in his possession a DVD rental from seven years ago that was under Sheldon's name, and that Leonard was supposed to return. After a good amount of time passed, Leonard figured to keep the DVD since nothing bad had happened. Leonard never told Sheldon about it as he knew Sheldon would "overreact". On the contrary, Sheldon outwardly remains relatively calm, but he figures that Leonard needs figuratively to walk a mile in his shoes to understand how upset he really is about what Leonard did. He makes Leonard do something that he knows will bother him until he returns the DVD, namely wear an ugly wool sweater against his bare skin, the sweater to which Leonard is probably allergic. To prove a point, Leonard agrees to Sheldon's payback. But Sheldon has in his possession some information that he knows will make it a little more difficult for Leonard to endure what Leonard believes will be an easy task. Still, Amy tries to figure out why Sheldon seems so calm about the situation. Meanwhile, at the Cheesecake Factory with Penny and Bernadette, Amy recognizes another one of the customers: Raj's old girlfriend Lucy. Penny wants to stand up for Raj against Lucy, who broke up with Raj via email. Penny's actions have some expected and unexpected consequences.—Huggo

Sheldon asks where the Skeeball tickets are. After three years, Sheldon has decided which prize he wants at the arcade. Sheldon implies he wants a squirting lapel flower. Leonard finds the tickets and a sweater his aunt made for college that is bright red, itchy and has "Lenny" written on the front. \ Leonard tells Sheldon to not flip out. Leonard pulls out a DVD that they rented on his card and should have returned a long time ago (seven years). He begs for Sheldon to remain calm which Sheldon does so and asks him to return it. Sheldon agrees and that freaks out both Leonard and Penny because Sheldon is being surprisingly reasonable.

Leonard starts to discuss with Sheldon, what it means to not freak out about the DVD. Don't fixate on it, don't wake him up in the middle of the night, don't nag him while he's on the toilet. Sheldon describes it as an itch in his brain that he can't scratch. Sheldon agrees to not pester him about the DVD if he will wear the sweater until the matter is resolved with nothing underneath it. Leonard has said that the sweater is itchy and uncomfortable; Sheldon feels the same way about unresolved issues. Sheldon wants them to share the experience and Leonard mistakenly agrees. Sheldon claims that the video store went out of business years ago as the sweater starts to bother Leonard so he scratches.

Amy and Bernadette are at the bar and Penny has not yet delivered their drinks. Amy notices Lucy (Kate Micucci), Raj's former friend at another table. Penny wants to go over to talk to Lucy because she hurt her Indian friend. She identifies herself as Penny to Lucy, Raj's friend. She asks how Raj is and tells her that he is good. Then she asks why she broke up with him by an email. Lucy tells her she guesses that it was easier. Of course it was easier for her, not for him. Lucy asks for a different waitress. Penny continues that she can sit there while Raj is at home a blubbering mess. Lucy remarks that she thought she had said he was fine. Penny tells her that she may be a bad waitress; however, she is a bad person.

Sheldon, Howard and Raj and having dinner together in Apartment 4A while Leonard fidgets in his itchy sweater. Leonard isn't going to take it for sleeping. Leonard's next step is to go downtown, find the name of the store's former owner and then return the DVD while also paying the fine to prove to Sheldon that you can solve the problem without being a complete lunatic.

Over in Apartment 4B, Amy and Bernadette are scarfing down popcorn and junk food. Penny comes in and tells them if they were hungry, they should have ordered something at the restaurant. Bernie tells her that they did and Penny never brought it to them. She tries to remember their order and gets it wrong. Then they want to know how she is going to deal with Raj since she told Lucy he was a pathetic mess. Penny feels that they are overreacting and Raj is going appreciate her watching his back. Raj comes over and screams at Penny, asking what is wrong with her. She ended any chance of them getting back together. Raj then gets a text from Lucy asking her to meet him for coffee. Now he loves Penny and gives her a big hug.

Sheldon is in his office working on his white board when Howard comes in. Leonard found the name of the DVD store owner and happily says that he died in his sleep at the bottom of a pool some time ago. Since he can no longer return the DVD, he considers the matter resolved. He removes the sweater displaying the rash he developed and puts on a clean T-shirt. Howard suggests that he find the store owner's next of kin. Sheldon likes that idea which infuriates Leonard. Howard hands him back the sweater.

At the Wolowitz's Raj is having dinner and wants to know how to handle meeting Lucy. Howard says that he can't let her know he is hurting, try confidence.

Over at Penny's apartment Leonard continues to scratch himself while wearing the sweater. Leonard is searching the Internet for a stupid relative of the stupid store owner so he can look at the expression of Sheldon's stupid face. Leonard is practically in tears as Penny tells him to just take it off. For Leonard it's the principle of the thing.

Sheldon is sitting at Amy's place. Amy complements him on handling the DVD situation with an impressive amount of maturity. Sheldon doesn't know why it shouldn't surprise her since he is a grown man so evident by his sport coat and real flower in his lapel. Sheldon wants her to answer the question what does his flower smell like. Amy wants to know the real story behind this DVD. Sheldon proposes that he bought a book about how to cope which told he to stop and smell the flowers. Amy asks, "Seriously?" to which Sheldon says please. She leans over and then the flower falls off his coat which is now spotted with water.

At the coffee shop, Raj greets Lucy and tells her how good it is to see her. He ordered her a cappuccino which she remembered as her favorite and also a crumb cake which he later remembered was his favorite and he ate it. She apologizes for breaking up with him via email. Raj says that he hopes that they can hang out again as friends. Lucy explains that she kind of seeing someone now. Raj needs it explained to him that it's not him that she's seeing. Then he is back yelling at Penny that is all her fault. She then tells him that she has a friend she can fix him up with. Now he loves Penny again.

Amy and Sheldon are now having tea at Sheldon's place. Sheldon wonders how he can conceptualize dark matter, but not able to fix a novelty squirt flower. Leonard storms in telling him that he is out of options. He has found no next of kin. He went to the Armenian church where his funeral was held and found out that no one attended. Leonard says that the search is over. Sheldon suggests that he go to Armenia or Lebanon. He is not going overseas just to return "Super Mario Brothers: The Movie". Finally he asks Sheldon why the DVD is not bothering him. The DVD was checked out on his card and could be ruining his credit score. Seven years ago Sheldon found out it was late and paid for it. He was going to mention it then, but he thought that someday this time could be a teachable moment. Hearing this comment, Leonard goes berserk - he rips off the sweater and hurls it in the trash, before yanking the freezer door open and pulling out a couple of frozen food packs to apply to his chest. Amy then comments that the whole thing was diabolical. Sheldon agrees and then asks if she knows what it is like to wait for years never knowing if you'll finally get satisfaction.

Raj is on his date telling the Indian girl that she is so pretty he can't believe she doesn't have a boyfriend, which she doesn't. Then Raj explodes that he doesn't believe her and accuses her of lying to him. Then he says that he is so desperate, which he is willing to be the man she has on the side. Then the girl is screaming at Penny, "What is wrong with you?" Then Penny is screaming at Raj, "What is wrong with you?" Finally Raj is screaming at a mirror, "What is wrong with you?"

Title reference: Leonard wearing an uncomfortable sweater to simulate Sheldon's sensation of an "itchy brain" when confronted with an unresolved issue.