Wilson is preparing Sara's latest insulin injection when he finds himself feeling sneezy and generally allergy-ridden. He knows exactly who to blame for this, and goes to work to accuse House of planting something he's actually allergic to in his apartment to make him think he's allergic to Sara. House says Wilson sounds paranoid, which is a symptom of being a Crazy Cat Lady. Wilson says he knows what he's allergic to: ragweed and dandelions. He is not allergic to cats. And even if he was, it's not like he'd suddenly start sneezing after having the cat with no problems for days or even weeks. Try harder, House. He says if Wilson wants to prove that he can be sociable and meet women, even with a pet cat, then he'll join House on a boys' night out.
Chase prepares Nadia for her dialysis. He mentions her sister, and Nadia says he must think she's being too hard on Elena. Chase says he understands that grudges can be difficult to get past, but Nadia says this isn't a grudge -- it's "common sense." Elena has hurt Nadia more than she's helped her, so Nadia is better off without her. She claims that because she has a perfect memory, she doesn't "edit" her memories like everyone else does to keep from remembering the painful truth. I don't know; it seems to me like Nadia is forgetting one very big part of her relationship with her sister: that she's her sister, and she loves her. And that has nothing to do with whether or not you have a perfect memory and can keep a mental tally of pros and cons. It might make it more difficult to forgive someone when you can remember every thing she said or did to you and how awful it made you feel, but it shouldn't make it impossible. Especially since Nadia should be just as good at remembering the good times as she is the bad ones. And finally, she's had this memory since puberty, so why hasn't she learned how to deal with forgiving people or accepted that not everyone can remember things as well as she does? This is like The Flash challenging mere mortals to a foot race and then getting angry when they aren't very good competition. Chase says if Nadia can never forgive anyone then her life must be pretty lonely. Nadia claims that she does forgive people, but only if they've done more good things for her than bad. And then she stops being able to breathe, so there goes her friendly relationship with her lungs.
Foreman brings Taub to his home. Taub is surprised by Foreman's personal style, saying he always figured Foreman's place would have shag carpeting and a "Mod Squad vibe." Oh, it's probably best that we don't bring up the names of shitty movies this show's cast members were in. I'm sure Peter Jacobson has a few clunkers on his résumé, too. Foreman scowls and tells Taub he's only allowed in the dining room and Marcus's old room, as Marcus moved out to work for their uncle in Florida. Sounds like Foreman and his brother didn't have a very happy reunion after all. Also, I guess Orlando Jones had better things to do than collect a paycheck for appearing on this show again. I can't imagine what those things are, but good for him. Foreman says Taub is only allowed to study and sleep from now until the exam. Taub doesn't think this sounds like fun and has no desire to abide by Foreman's rules. Foreman says if Taub fails his test the second time and House makes Foreman's life miserable, Foreman will kill Taub. Honestly, if Taub loses his job at PPTH because he failed a test twice in a row after everything else he's blown, I think Taub will kill himself and save Foreman the trouble.
House stops by Nadia's room to figure out what caused her respiratory distress. While Chase and Martha assume it's another symptom of her mystery disease, House spots hives on Nadia's legs and guesses they're looking at an allergic reaction. Chase doesn't see how, since Nadia is on steroids right now. House says a really bad allergic reaction would show up even with the steroids. His guess? Nadia is allergic to the dialysis. That's bad news for Nadia, since she kind of needs the dialysis for her failing kidneys.
In the hallway, Martha asks what they should do next. "Look for another case," Chase shrugs, figuring that Nadia is going to die from kidney failure before they can figure out what's wrong with her and treat it. Martha points out that Nadia can get a donor kidney from a family member. Apparently the only family member she has is Elena, and she's kind of mad at her right now and probably not in a kidney-donating mood. Martha says she might have been if they hadn't interfered and made things worse between the sisters. Chase doubts it, sharing with House and Martha about how Nadia keeps score of the good and bad things people have done for her, and used it to determine that her own sister doesn't deserve her affection. Chase sounds disgusted with Nadia for this, but House clearly admires Nadia's talents as he says that she's probably right about Elena and that her memory gives her a "pure and objective view" free of agendas or emotions. Um, just because Nadia's memory is perfect doesn't mean it isn't subjective. People are subjective, and they see things subjectively. House says that, unlike Nadia, Elena has plenty of agendas and emotions, so Martha can go work off some of her guilt by exploiting them to get Nadia a new slightly used kidney. Martha doesn't want to, saying she's not "good at that type of thing." That, and she's scared Elena will call her a bitch again. House doesn't care.
Martha dutifully goes to Elena's house and tries to apologize, saying she's not very good with people since she's more of a "book and equations" person and people are so "random and messy." Um, who wrote this episode? Was it a robot? Because many of the characters are certainly being written as they were robots this week. Martha says she doesn't have much experience with sisters, either, since she doesn't have a sister although she did have a female cousin, and when they got their periods at the same time "it was like gladiator school ... " Elena saves Martha from herself at this point and asks if Martha is here to ask her to donate a kidney to Nadia. Martha says she is. Elena says she will. "It might not fix your relationship. Uh... probably shouldn't have said that," Martha says. Ha! I enjoy Martha when she isn't annoying the shit out of me.
Meanwhile, Foreman and Taub are hard at work studying nothing but a videogame. In fact, it's that videogame we've seen before. Twice now! I guess the creator was so happy to be cured that he gave everyone on House's team their own free copy. Foreman says they have five more minutes of playing before Taub has to take a practice test. Taub sighs and admits that he didn't fail the first test because he was sick. He "choked." Foreman pauses the game and asks Taub how he could choke on a simple test when he makes life or death decisions under incredible pressure every day. Taub says the first time he took the pathology board exam, he got a perfect score. So when it came time to take it again, all he could think about was that whatever score he got would show how much worse he's gotten since then. Foreman says Taub has to stop freaking himself out like this. Taub doesn't think that's possible, considering that he failed the first test when he still had a marriage and a home, so he doesn't have much hope for things this time when he has that much more to lose. Foreman un-pauses the game and shares with Taub that he feels the pressures of the job sometimes, too -- waking up