House talks to Joe, who also has a TV on in his room and so knows that Senator Hal just threw him under the bus to save his own chances of re-election. House says he thinks Senator Hal screwed Joe in more ways than that -- Hal has symptoms of hepatitis C, which House thinks Joe has too, caught from the senator. Joe denies sleeping or shooting up with Hal, but House says they must have shared something. What about a straw when they snorted coke together? That seems to ring a bell for Joe, who says he'll deny everything and asks how he could have hep C when he was tested for it earlier and it came back negative. House says that Joe's liver was taking a page out of Joe's campaign tactics book and hiding the truth from the test by producing cryoglobulins and causing a false negative test result. The plasmapheresis filtered out any other testable signs of hep C. So House knows Joe has hep C but no way to actually prove it. No matter; he'll shoot Joe up with some interferon to treat it anyway.
Still in jail, Foreman and Chase have plenty of time to come up with theories on why Taub hates Martha. Foreman says perhaps they had met before, and then they're interrupted by a guy using the toilet in the corner of the room. While Taub freaks out about the open display of pooping going on behind him, Chase and Foreman ask if he slept with Martha before or if she shot him down. Taub finally reveals the truth: he interviewed her when she applied to Hopkins and even though they spoke for an hour, she didn't remember him when she walked into the meeting room. Since Martha's genius memory is pretty damn good, Taub must be very forgettable.
House finds Martha making her way out of PPTH and informs her that she has been re-re-hired. Martha tells him to find another sounding board because she has enough self-esteem not to subject herself to this. House just keeps going, saying that Joe's hep C isn't responding to the interferon so he needs suggestions for what else to treat him with. Martha is about to walk out, but House says she can't, because then she'd be quitting. He's right. Martha says there's a German study where 15% of hep C sufferers were cured by being infected with hepatitis A. The other 85%, however, kind of died from having hepatitis A and C. Like, of course. What a horrible study. Who would volunteer to take part in that trial? Although it is a German test, so perhaps they didn't actually ask for volunteers. Martha says they could try treating Joe with someone that "mimics" hep A. Of course, House is ready to just give Joe the real thing.