Back in the meeting room, Martha M. Masters cheerfully reports that brain involvement has definitely been ruled out and they can now focus on other diagnoses that involve the heart and the lungs. House would rather not, as his new theory is that Jack didn't jump on the tracks to save a stranger, but someone he already knew -- he was having an affair with the woman, Chloe, and her seizure was not caused by epilepsy as they all assumed, but by the same thing Jack has. Martha M. Masters would rather take a culture of Jack's sputum (ew) and look for an infection, but House decides the lack of white blood cell count elevation rules that out and it also doesn't fit in with his Jack-is-not-a-real-hero-because-those-don't-exist theory. Some kind of toxin in Chloe's apartment, however, does.
Chase and Taub break into poor Chloe's apartment, as if she hasn't had enough to deal with lately, and Taub immediately complains about how ridiculous this is. Chase assumes Taub's crankiness is due to another fight with Mrs. Taub, but Taub says that, on the contrary, they've been having lots of sex lately. Which actually bums Taub out because Mrs. Taub hasn't been this horny in years and he's starting to suspect that Phil is who she really wants to have sex with, but since he's not there and Taub is, she's settling for him instead. Chase, whose marriage ended after like three months in divorce, doesn't see the problem in any of this. And while he finds a CD from Jack's band that proves he and Chloe had a relationship after all, Taub finds a can of roach spray that could be the toxin that made them both sick.
House does Clinic duty. His latest patient is none other than Murphy Brown, although he doesn't seem very impressed by her or her complaint of feeling tired and having pain in her shoulder when it's cold, especially since all of her tests say that she's perfectly healthy. House is typically short with and condescending to her, causing her to ask why doctors always seem to think they are so much better than everyone else. House thinks it has something to do with how they save people from dying and stuff. Murphy Brown keeps talking, saying that her daughter is a doctor and acts the same way, always dismissing her mother's concerns. "She sounds smart," House says, still not knowing where this is going. Murphy Brown waits for him to almost reach the door before dropping the bomb: House is "shtupping" her daughter. Because Murphy Brown is totally Cuddy's mom! Hooray! A rather shell-shocked House makes his way towards Cuddy's office, but she isn't there. He leaves a message on her phone instead: "we have a situation."