At a fundraiser for his Presidential run, Senator Gary Wright is overcome by illness and collapses. At the clinic, Volger asks House to give a speech at a pharmaceutical meeting and offers to relieve House of staff-firing duties if he does so. House also has to examine Wright and believes something is up when he shows a lack of reflex. While they wait for the MRIs, House examines a woman who was pregnant and had a miscarriage but claims she hasn't. House orders a brain biopsy but Cuddy overrides him and they put it to Wright, who agrees. The tests prove negative for a brain tumor but shows a lesion caused by toxiplasmosis – indicative of AIDS.
Wright denies the possibility and refuses to take the pills for treatment, then calls for anonymous testing for AIDS and regular tests for cancer as "cover." The staff find out about it but House isn't interested in Cameron's thanks. The female patient returns with a hickey but still claims she hasn't been with anyone and House orders tests for alcohol and date-rape drugs. The AIDS test on Wright proves positive and when House tries to get a list of Wright's sexual partners, he still claims he couldn't have gotten it from sex. Later Wright's legs go out and House concludes the AIDS test was a false indicator – a second test proves he doesn't have AIDS but he's dying of something else.
Wright's muscular condition continues to deteriorate, while the woman's tests prove negative for any drugs. Now she has a new symptom – a rash on her butt that is a carpet burn. She's waking up exhausted because her ex keeps bothering her. He has her go into a sleep lab while they run more tests on the senator. One shows he has several enlarged lymph nodes but nothing definitive. House confronts Chase, knowing he's lied and is spying for Vogler, but Chase merely notes there's nothing House can do. House suspects Wright has leukemia of the spleen, which may cause his death if they run another biopsy. Before they can run the test, Wright goes into respiratory distress so they can't do the biopsy.
Wright tests negative for leukemia but positive for Epstein-Barr, House determines the woman is sleepwalking to her ex-husband, then takes Wright off the respirator. He concludes that Wright didn't have a childhood accident that led to a scarred tongue, but that he suffers from epilepsy. The drug he took, in combination with Epstein-Barr, causes weakening of the antibodies. They give him the proper treatment and he shows rapidly recovery, while House considers his speech. Finally the day comes, and as his staff look on, he gives . . . a one-sentence speech. After Vogler threatens him again, House adds the truth – that the new drug is the same except more expensive. House goes back home to play the piano and gets a visit from Cameron, who quits because of her feelings.