A man named Rob doesn't understand why his daughter Alice is not interested in the rides at the carnival. On one ride, the little girl begins clutching her stomach and screaming in agony.
At the hospital, Rob argues with his ex-wife, Edie, about taking Alice on the ride. Cameron is more interested in Alice's medical history, which does not indicate any abdominal problems. Edie snipes that Rob only had Alice for two days and she ended up in the hospital.
House pulls Cuddy out of a meeting with two potential financial donors. He wants his pills. She walks over to the pharmacy, grabs a cup with two Vicodin in it and hands it to House. His days of free-flowing pills are over. No doctor in the hospital will make a move now that Tritter is watching them.
As the doctors mull over Alice's case, House barges into the office, heads straights to a textbook where he has hidden a bottle of pills cut inside the pages. House then takes a quick glance at Alice's CT scan and declares gallstones. Although six year-olds don't get them, they could be vanishing gallstones. He considers that Alice had one and it passed, but more are probably hiding in her gallbladder. House orders an ultrasound. If he's right, they can remove the gallbladder in order to biopsy the stones.
The team performs the ultrasound and they bicker over Chase's eagerness to adhere to House's instant diagnosis. Yet Alice does indeed have gallstones. Chase breaks the news to the parents, along with the plan to remove Alice's gallbladder for a biopsy. Rob quickly agrees to the procedure, but Edie doesn't.
Cuddy finds Tritter in an office poring over boxes of files. She accuses him of making this personal, and asks if he thinks Wilson deserves to have his life turned upside down. Tritter says this is how he gets what he wants. If squeezing Wilson doesn't work, it will eventually work on Foreman or her.
House berates Edie for refusing to consent to Alice's surgery. Edie stands her ground, pointing out that gallstones are basically harmless. House brings a judge into the hospital and attempts to bully the woman. The judge turns to Cuddy for her opinion on House. Cuddy agrees with the judge that House is indeed a jerk, but he does know what he's talking about. The judge orders the surgery.
The procedure goes well, but the biopsy is negative. Edie bitterly points out that her opinion about the surgery as unnecessary has been proven correct. Alice begins complaining that her stomach hurts, so Foreman takes a quick peek. He finds a blistering rash breaking out across her midsection.
The next day, House questions the team about the rash. His doctors are more concerned with why their bank accounts have been frozen. They demand that he talk to Tritter and do something about their money. House tries to get past this, and he instructs his team to do a scratch test on Alice for allergies, which is what Cameron suspects. When the allergy tests are negative, they are to start broad-spectrum antibiotics. House thinks it is a bacterial infection.
The scratch test gets many results. Each one has come back with a positive allergy result. Looking at Alice's back, House still rejects allergies and points to bacteria as the cause. He is sure that bacteria got into the scratches. Chase insists that infections radiate, which isn't what Alice's rash is doing.
House gives Alice of bite of the peanut butter sandwich he's holding. He then asks Foreman and Chase if Alice is allergic to everything except peanuts. Chase points out that if she is allergic, then antibiotics could cause a massive reaction. House again insists that she isn't allergic. Chase moves to grab the antibiotics, but Foreman stops him. He tells him that he is correct and should stand up to House for once. But before Chase can start an IV, Rob steps in and refuses to allow it.
The case is reverted again to the judge, and House argues against the father's decision. The judge becomes tired of House contrasting the parents on every decision and she grants temporary guardianship to Cuddy. Against using broad-spectrum antibiotics in the event that Alice is allergic, Cuddy decides to allow just one antibiotic -- metronidazole -- as a test.
Tritter interrogates Foreman and mentions Foreman's brother, Marcus, who is doing time on a drug charge. If Foreman testifies against House, Tritter will see to it that Marcus is free within two months. Foreman still doesn't budge. Tritter observes that Foreman is just as cold as House. Yet he is convinced Foreman will take this deal because he hates hypocrisy. House has had a thousand chances, and Foreman himself has had a couple. Marcus only got one chance.
Cuddy checks in on Alice, who sleeps peacefully. There doesn't seem to be any reaction to the metronidazole. The parents fight about Rob's decision to withhold antibiotics and Edie angrily declares that she's suing for full custody as soon as they get out of the hospital. Alice's heart starts racing and her blood pressure rises. Cuddy realizes that the parents' arguing is giving Alice an anxiety attack. She kicks them out of the room.
The next morning, Chase announces that Tritter froze his accounts as well. Edie comes into their office wondering where Alice and Rob are. Chase rushes off to get security and sees Rob holding an unconscious Alice in his arms. She's as stiff as a board.
House mocks Cuddy's decision to skip broad-spectrum antibiotics. Foreman injects Alice with diazepam to relax her and points out that muscle rigidity is almost exclusively neurological. Cameron guesses at neuroaxonal dystrophy. Ignoring the patient, House starts yelling at Cuddy to give him more pills. She refuses.
House accosts Rob and Edie about which one of them gave Alice an aspirin. He believes that Alice has Reye's syndrome. When a child with an infection takes adult aspirin, it affects the brain and liver. Neither of them did, but Edie says that a babysitter might have administered them the night before she came to the hospital. House orders Cuddy to put Alice on charcoal hemoperfusion, and then he demands more pills for himself. Cuddy pulls a bottle out of her pocket and taps two pills into House's palm.
Cameron gets her turn to sit down with Tritter. She refuses to participate, so Tritter brings up her past. She used to be somebody who always did the right thing until she starting working with House.
Chase meets with Tritter in the hospital cafeteria. Tritter explains that he's going to unfreeze Cameron and Foreman's accounts, but not Chase's. They both know that Chase's account never was frozen. Chase lied about that to the others so it wouldn't look like he had been singled out. Yet now that the accounts are open, people will notice the two of them having a very pleasant lunch in the cafeteria. House will eventually put two and two together.
Cuddy explains the procedure to Alice. The little girl admits that she is scared of her parents. As soon as she's better, her parents will split up again. As the procedure is underway, Alice starts screaming that her arm hurts. Foreman suspects it might be a clot, so Alice is rushed into surgery.
Foreman successfully removes the clot, but Alice's body temperature begins increasing. The O.R. is out of ice packs and cooling blankets, and they need to cool Alice down before her brain melts. Cuddy yanks the wires out of the monitors and takes Alice into her arms. She rushes the girl into a cold shower. Cuddy shows House the rash that has returned to Alice's arm. Increasingly tense over his pain and the Tritter debacle, House angrily declares that he was right about the broad-spectrum antibiotics. He then icily tells Cuddy it's a good thing she failed to become a mother because she sucks at it.
House launches into a differential diagnosis with the team. With the arm rash, they never treated Alice's arm. Yet now it is so intense that simple antibiotics won't work. The team has no answer. Cameron says that Tritter released their accounts. The team all suspects that somebody talked. Cameron finally throws out Rocky Mountain Spotted Fever and House orders doxycycline as a treatment.
The next morning, Foreman reports that the treatment didn't work. The rash is getting worse and spreading to her leg. House thinks that the infection has morphed and moved into Alice's muscle sheath. Foreman realizes that House is referring to necrotizing fasciitis, for which there is no cure. The only treatment is amputation. The team is loathe to amputate Alice's arm and leg with a confirmed diagnosis. House points out that they've waited too long and don't have time for a culture. If the rash spreads, Alice will die. The doctors continue to resist. House, in physical agony, snaps that just because Alice is cute doesn't mean she cannot have flesh-eating bacteria. Cute kids die and innocent doctors go to jail. He remarks that cowards like Chase, Foreman and Cameron won't stand up and do what's right.
House stomps into Cuddy's office looking for pills and the consent to amputate Alice's limbs. Cuddy and House break the news to Rob and Edie. They realize they have no other choice. Alice is sent into surgery. At the same time, the doctors sit in their office complaining about House. Cameron, still thinking about Alice, mentions the rashes. Perhaps Alice is allergic to surgical equipment. Chase, bored, begins shining a laser pointer on Foreman. Foreman complains that he's going to burn his retinas. Chase suddenly has an epiphany.
Chase races out to the lobby and finds House, shouting that he has to stop the surgery. Alice doesn't have necrotizing fasciitis. She has erythropoietic protoporphyria, which is a genetic condition that makes her allergic to light. Alice got worse every time she went under surgical lights. When Rob took her outside, she stiffened. House tells Chase to get out of his way. When he doesn't, House punches Chase in the face. Even House seems shocked by what he just did. Chase is still focused on Alice, and replies that light damages the blood cells. The damaged cells contain protoporphyrin build-up in the liver which shuts it down.
The call comes into the operating room as the scalpel moves toward Alice's shoulder. The surgeon stops just in time. Cuddy explains to Rob and Edie that Alice has always had this genetic condition, but it reaches critical mass around this age. Alice's life will be complicated but she'll live. When Rob and Edie ask how their daughter contracted the disease, Cuddy lies and says that both parents must be carriers to pass the disease along. She fears that another argument will break out.
That night, Chase finds Wilson in the doctors' lounge. He mentions that House screwed up Alice's case, but Wilson says that has happened before. Yet this time, when Chase told House what Alice's real condition was, House simply didn't care.
Wilson approaches Tritter and tells him he's going to need thirty pieces of silver.