A young couple are in a diner when two robbers holds them at gunpoint. Jeremy manages to get the drop on them but his wife, Tracy, starts to choke and collapses.
House's staff reviews the case and House is skeptical of the fact they're married at 20. House is more interested in the fact that Wilson is talking with a new nurse, Wendy and goes out to confront Wilson, who denies he's dating the woman. Chase suspects salmonella that covers the symptoms and House accepts the treatment for now. He then goes into the clinic to meet with a patient with a staph infection, Michael Tritter, who notes that House isn't getting away with his act and kicks his cane out from under him. House relents… slightly and gives him an anal thermometer, then leaves him in the room.
Foreman talks to Tracy and her husband Jeremy, who deny they're not smoking. She starts itching from a rash on her arm and House now goes along with Foreman's diagnosis of an allergic reaction. House suggests they put her on a treadmill and makes a wager with Foreman on the results. Tracy's stomach hurts her and Jeremy starts having similar pain.
While House leads the team on a diagnosis, he goes into the nurses' locker room to check out Wendy's locker and concludes they're going on a date, and bets Foreman $200 that they are. He sends Chase and Foreman to check out the couple's apartment and find that they use condoms, and Chase suspects they have gonorrhea. Tracy says she had a pregnancy scare and Jeremy used condoms, then complains it's a racial thing because they're a mixed-race couple. The tests for gonorrhea prove negative and House takes Tracy off the medicine to see if it's environmental. He then goes to Cuddy who insists he apologize to Tritter while denying she's pregnant despite House's suspicions. Meanwhile, Tracy wakes up to find Jeremy's father in her room breaking Jeremy's arm. It's an acute delirium and she goes into a coma.
The team puts Tracy into the MRI while Foreman talks to Jeremy who explains her hallucination and reveals his father was a drunk and killed himself after they eloped to get away from him. They eliminate the possibility of infection and House suspects it's environmental, but then suggests sarcoidosis. He takes the MRI to Wilson for a consultation and reveals he stole Wendy's personnel file. Wilson figure House doesn't want him to be happy, and says it's not sarcoidosis. House orders a biopsy for sarcoidosis anyway and Cameron suggests there's a conflict with the husband being the one to allow the treatment. Cameron goes to Cuddy who insists another legal guardian be appointed, but agrees to have Wilson talk to Jeremy if House will apologize to Tritter. He agrees but Jeremy would rather have the biopsy instead of her and tells them to stop treating him. House is angry at Wilson who doesn't back down, then tells them to cut the morphine on Jeremy. When his team refuses, House tells them to give him an opiate blocker to put him in pain so he'll allow the biopsy on Tracy. When his team still refuse, House gives them the medicine but after he leaves they realize he's slipped by them with a second dose. Foreman barges in as Jeremy goes into pain but insists on getting the biopsy and insists he loves her and will die for her.
House finally backs down enough to insist on a court order, but when he goes to Cuddy she ushers him into her office where Tritter is waiting for him. Tritter wants humiliation but House refuses to apologize. When he emerges he finds out that Jeremy's insides are rotting and he doesn't have sarcoidosis.
The couples' mutual conditions are worsening and House orders treatment for Tracy and removal of the dead bowel from Jeremy. But an analysis reveals high lactate levels and the intestine isn't dead. When Foreman mentions they ran off from his father, House questions the reason they ran away and realizes it's a DNA problem, angioedema, that prevents protein formation, and they both have it because they're stepchildren. Tracy starts to recover and Foreman wonders how they should tell them they're related but House insists he tell them. Foreman eventually tells them and they're not happy, even as he tries to assure them their feelings haven't changed.
Later Chase is comfortable with the situation although Foreman is upset and is heading out of town. House figures out that it's Foreman who's dating Wendy, not Wilson, and has to pay up on their bet. Foreman meets with Wendy but there are clearly a few issues between them. However, Foreman notices Jeremy alone and goes to talk to him. Wilson ends up back in her hotel room by himself, Cuddy's pregnancy test shows negative, and a speeding House is pulled over by a policeman… Tritter. Tritter notes House was taking a pill while treating and finds reasonable suspicion to search him and finds his vicodin stash. He arrests him for possession of drugs.