After the break, Chase says Nadia's heart problems rule out their Parkinson's diagnosis. Well, that's good news. But House only wants to know if Martha would ever sleep with a man who owned a cat, providing that she ever does lose her virginity. Martha says she would, figuring it's pointless to be appalled by or refuse to answer the question at this point. House says she would not, and she's a slut. Martha is used to this treatment by now. I don't feel sorry for her; she had her chance to quit last week. House asks the guys if any of them have ever owned a cat. They have not. House asks if they've ever had sex. They have. House's point is proven, even though no one else in the room really knows or cares what his point is. Oh, wait, no -- Martha does want to know, and asks him about it after suggesting that Nadia's heart is at the root of all of her problems. House refuses to tell her while asking her to tell him more about her theory. Martha says Nadia's heart problems only began when she was under the stress of seeing her sister. House says they'll have to try stressing Nadia out again to see if it causes another arrhythmia. Instead of sticking her on a treadmill like usual, though, House suggests they stick her in a room with her stressful sister. And then he and Martha have a weird staring contest for like a minute while they wait for the scene to end.

House confronts Cuddy, accusing her of lying to him about Wilson's cat. Cuddy says she never lied -- she simply said she didn't know anything about Wilson having a friend named Sara. Sara is a cat, and everyone knows that cats are friends to no one. Cuddy doesn't think it's a big deal that Wilson has a cat, but House claims that after Wilson's second divorce, he got a three-legged Siamese cat and turned all weird and anti-social until one of his windows was left "suspiciously open" and the cat got out, thus breaking its spell over Wilson. Cuddy warns House to leave both Wilson and Sara alone. House has no intention of doing this.

Elena hovers over her sister, who is strapped down on some medical evaluating table thing. Elena apologizes for giving her daisies, saying she always forgets if Nadia loves them or hates them. Nadia says she can tell her exactly how many times she's reminded her, apparently still not realizing that not everyone has a memory like hers and so mistakes will be made. In the booth, Chase says Nadia's heart rate isn't moving, so Martha will have to go out and try to start a fight between the sisters. Martha doesn't want to, but Chase says she'll be able to tell the truth while at the same time help their patient's medical needs. Martha can't resist an opportunity like that, so she walks out and immediately starts talking about the time Elena totally ran Nadia over in her car. Nadia can see it all like it was five seconds ago, of course (although... didn't they say her perfect memory started at puberty? And she was hit when she was a child? I guess being hit by a car isn't something you forget, though). Elena is all mad at her for telling her doctors about that at all, but Nadia says they asked her if she had any broken bones. Elena quickly says that she totally checked her mirrors before backing out. I think someone's being a little bit too defensive. Nadia, on the other hand, thinks Elena "didn't care enough" to check those mirrors, much like she "didn't care" and ruined Nadia's 23rd birthday. And, Nadia says, Elena is only "acting" like she cares about Nadia by visiting her now. How can Nadia have a perfect memory and not realize how unfair she's being to her sister? I mean, yeah, Elena ran her over, but sisters run each over with things all the time. I'm pretty sure I ran my little brother over with a bike at least five times growing up. Not a car, though, because unlike Elena, I always check my mirrors. Anyway, Martha's mission is soon accomplished as the stress causes Nadia's heart rate to rise again. Martha tells Elena to leave the room. Nadia screams it to her.