Ten-year old Jessica Simms tells her mother that she isn't feeling good and doesn't want to go to school. She admits that she thinks the kids at school hate her. At school that day, Jessica is jumping rope in gym class when she complains that her chest hurts. The teacher pushes her to finish, but Jessica collapses. Her heart stops beating.
At the hospital, Cuddy asks House if he's made a decision on who to fire per Vogler's order. House wants to stall as long as possible, and she grants him a week.
In the elevator, Cameron brings House up to date on Jessica. The team can't believe a 10-year old would have a heart attack but six tests proved it true. Chase thinks it's a simple case of Jessica being too obese and depressed. House though believes that Jessica's legion of previous doctors have missed something.
Foreman wonders about a genetic condition. Cameron suggests Metabolic Syndrome X, which could cause a heart attack with high enough blood pressure. House orders a hyperinsulinemic euglycemic clamp. But before dispatching his staff, he informs them that he'll have to cut one of them by the end of the week. They're all shocked, and Cameron and Foreman think they need to stick together through this.
Cameron explains MS-X to Jessica's mother and says it can be controlled through diet and exercise. Mrs. Simms complains that doctors never see past Jessica's weight. Chase and Foreman try to cajole Jessica onto a scale as part of their standard tests.
Afterwards, Chase is upset that Foreman told the little girl that she will probably grow into her body. He is also annoyed that Cameron tries to sugarcoat body image. Foreman counters that Chase is probably uptight because he knows he's the one who will be cut.
House's team conducts the HEC test on Jessica, who freaks out and tries to rip out the IV. The doctors and Mrs. Simms all struggle to restrain her. After sedating Jessica, Foreman explains to Mrs. Simms that psychosis brought on by hypoglycemia is common during HEC tests.
From the results, House declares that Jessica isn't hypoglycemic so her psychosis was caused by something else. Chase suggests blood clots, which Cameron shoots down. Yet it could have been brought on by liposuction, which isn't in Jessica's medical file. House considers other weight treatments like diet pills, which wouldn't show up in toxicology screenings.
He orders the patient to be put on heparin and warfarin to prevent further clotting, placing Foreman in charge of locating the diet pills. Foreman chides House for pitting the doctors against each other. House asks Foreman whom he would cut. Foreman nominates Chase because he believes he doesn't appreciate the job. House says he's surprised that Foreman would have named anybody.
Vogler questions Cuddy on House's staff cut and what he has been telling the team. Vogler offers to help if Cameron is the one who's let go.
Foreman asks Jessica's schoolteacher if she ever saw Jessica with pills. He learns that Jessica doesn't have any friends at school, so the teacher directs him to Jessica's assigned 6th grade "buddy." The buddy tells him that Jessica always runs laps at recess because nobody will play with her. The girl says that she totally busted Jessica taking drugs one day.
Although Mrs. Simms adamantly denies giving her daughter diet pills, Jessica admits to taking them on her own. Jessica breaks down in tears and says she took them because she feels ugly and disgusting. The pills seem to explain all of her symptoms. Yet the doctors later find Jessica with huge, bleeding sores on her body.
In the office, House thinks the warfarin they gave Jessica led to skin necrosis, but Cameron says they started heparin first. House asks if anybody actually saw Cameron administer the heparin. When there's no answer, he has the team give Jessica an unfractionated IV heparin and low molecular weight heparin by subcutaneous injection right away.
Out in the hallway, Cameron lights into Chase for leaving her dangling in the meeting. The team is falling apart.
Vogler takes Foreman aside and asks if he likes working for House and values his job. Foreman responds in the affirmative.
Cameron is studying in the lab when House drops in on her to ask about the mistake with the heparin. Cameron insists that she didn't screw up but that she doesn't have another explanation. House then asks her who she would fire. She suggests that everyone take a pay cut so that they can all stay.
The next day, House announces to Vogler and Cuddy that he's made his decision. He wants to push for a pay cut across the board so that everybody can stay. Vogler rejects this because it's not about the money. He wants to know that House will do whatever Vogler tells him to do, no matter how distasteful.
House catches up with his team, who reports that the necrosis is getting worse. Wilson thinks that if they don't stop it from spreading, it will kill Jessica in about three hours. They need to cut it out before it penetrates the abdominal wall.
Wilson and Foreman break the news to Mrs. Simms that a radical mastectomy may be Jessica's only chance for survival because warfarin-induced necrosis attacks fatty tissue.
Cameron barges into House's office, accusing him of insisting that she made a mistake with the heparin so that he has an excuse to fire her. He counters that maybe she actually did make a mistake.
Cameron wonders if House can't deal with his feelings for her. House says that she's the only one who has expressed feelings and maybe she's acting this way because she wants to be fired. Meanwhile, Vogler tells Chase that if he's the one fired, then he's going to need a new mole on House's team. Chase complains that he's been feeding Vogler information only to protect himself.
There is no change in Jessica's necrosis. House wonders if Cameron didn't actually screw up, but they don't know what else it could be besides warfarin. Chase posits that maybe Jessica's fatness is a symptom, not a cause. Could it be hypothyroidism? The parents are both big and tall, but Jessica's short.
House starts putting it all together. Stunted growth, high blood pressure, blood clots and obesity are all symptoms of Cushing's disease. It can even explain the necrosis in rare cases.
Foreman points out that blood tests have not shown abnormal cortisol levels, but House says that is cyclical. They just haven't caught it at the right time. With only one hour left, they weigh the options between performing the mastectomy and treating her for Cushing's. If they're wrong on Cushing's, Jessica will die.
House orders a quick MRI to look for what could cause hypercortisolism. Foreman and Chase study the brain scan. Chase spots a tumor on the brain, indicating Cushing's disease.
Foreman explains the situation to Mrs. Simms. The surgery is quite dangerous because the tumor is located between the cavernous sinuses, an area that controls eye movement, and the major arteries that feed the brain. The surgeon will make an incision under Jessica's lip and insert a fiber optic microscope. He will then go through that incision to chop the tumor into pieces for removal. After a few hours, the surgery ends in success.
A week later, a slimmer Jessica is back for her checkup. Chase, Foreman and Cameron are all happy to see her doing so well.
House arrives for his meeting with Vogler and Cuddy. House nominates Chase to be the one who gets fired. Vogler rejects that and orders House to pick someone else. If he doesn't, the whole department is gone.