Foreman checks up on his secret Cottage team who are supposed to be busy doctors but have plenty of time to do things like stay in a shut-in's house for days and take on extra cases. I'm not complaining, though -- I love seeing them back in differential action! Chase diagnoses meningitis, but Foreman says all tests have come back negative. Cameron is being a party pooper, and tells Foreman that he's playing a dangerous game taking on two cases at once, and could compromise patient care. Cameron knows a lot about compromising patient care because she gets yelled at for doing it often. Chase goes for stomach cancer. Foreman thinks porphyria is more likely. Well, if he's so good at coming up with the diagnoses himself, then why does he need Chase and Cameron? "Neither's perfect," Cameron says, so helpful. Foreman says they'll test for both. And by "they" he means Chase and Cameron.
Foreman stops by his real patient's room, where Hadley is trying to explain their latest stress diagnosis. Sophia notes a lack of Kumar in the room. "There's four of us. It's my turn," Hadley says. Sophia is not amused. Would you be? She's probably heard about how Hadley's patients either die or are properly diagnosed by someone else. "I'm sorry I lied about my parents," Sophia says. Hadley takes up the cause of womankind and tells her that she did what she thought she had to do. Foreman pipes up that Sophia should be feeing better soon if their latest diagnosis is correct. In an effort to not stress Sophia out any further, Hadley dwells on her rape, urging Sophia to file a police report against her father for closure purposes. She says continuing to not address the rape won't make it go away. Sophia points out that nothing will make it go away. Oh yeah? What about a time machine? Sophia says that reporting her father will just label her as a rape victim. "It doesn't have to define you," Hadley whispers, so caring. Sophia points out that it already has where her doctors are concerned. Meanwhile, Hadley is so wrapped up in her patient's personal drama that she isn't noticing an actual medical problem. Fortunately, Foreman's there to notice that Sophia's pee is brown. See? That's why House needs Foreman. To catch what Hadley misses. Which is everything.
After the break, Taub announces that Sophia's discolored pee has been caused by "shredded red cells." Oh, that sounds extremely not good. Kumar and Hadley both come up with dirty factory related diagnoses, but Foreman says neither of them explain the initial lung symptoms. House has different idea. He asks about Sophia's homemade furniture. Hadley says it was made out of wood with little holes all over it. House knows that this means the wood was pressure-treated, and pressure-treated wood releases arsenic into the air when sawed. That's yet another reason why Sophia should have just gone with stuff from IKEA. It's cheaper and easier than making it yourself, and you can't get poisoned! Foreman gets a page and can't hang out there any longer. He tells the kids to test a strand of Sophia's hair for arsenic since it won't show up on blood tests, which all of them should have known in the first place. Foreman takes off, and House nods at the Cottages to get arsenic testing.