A teenaged factory worker named Sophia clutches her heart and collapses on a conveyer belt. Pink foam comes out of her mouth.
When House arrives at the hospital, Wilson grills him on whether he asked out Cuddy. Kutner presents Sophia's case to House. She is an emancipated orphan whose parents died last year. House has a feeling she is just a runaway who is lying. He has Kutner and Foreman do an echo to find the extent of her heart damage.
Foreman privately tells House that he has been approached to help run a clinical trial. House does not give him his permission.
As they discuss their dead parents, Sophia tells Kutner that she does not do drugs. He finds that her heart seems healthy. Meanwhile, Thirteen and Taub check the girl's apartment where they uncover a glass bong. Back at the hospital, House considers whether not all heart damage is structural. Drugs may have caused an intermittent achycardia. He has Sophia started on beta-blockers. Foreman tells the rest of the team to page him if they need him.
As he attends to Sophia, Kutner alerts her to the fact that it might be vasculitis, for which steroids is the treatment. If she has been using drugs, this could kill her. She again denies drug use.
Cuddy approaches Foreman about the clinical trials. She hands him the file of a four year-old named Jonah who has vomited blood. Foreman tells the boy's mother and little brother that the steroids in his asthma inhaler can sometimes cause lesions in the digestive tract. Yet his CT and endoscopy were clear.
Sophia suffers a psychotic panic. Kutner and Taub rush to restrain and sedate her. The team reconvenes. Lab tests show the delirium wasn't caused by a metabolic problem. This annoys House. The psychotic break sparked a surge of adrenaline but not an irregular heartbeat. House asks what causes both lung issues and delirium. Foreman suggests Prinzmetal angina, which would make an artery in the brain spasm and could lead to the delirium and the pulmonary edema. House wants to give Sophia ergonovine and to run an fMRI. House insists that Foreman handle it, but Foreman tells Thirteen to let him know when she has everything set up.
Foreman tries to get Jonah to swallow a pill containing a camera but Jonah shuts his mouth tight and shakes his head no. His older brother is able to convince him to take the pill. Jonah starts to laugh. Foreman asks Cameron and Chase for a differential about uncontrollable giggling.
Foreman hurries in to Sophia's fMRI where Kutner notices something strange related to Sophia's conversation about her parents' deaths. She had been using the limbic region, which is for imagination and not fact. Kutner challenges Sophia that her parents aren't dead. She says she wishes they were dead because her father raped her.
The team discusses this development. There are no signs of spasm, impeded blood flow or brain dysfunction -- so it's not Prinzmetal's. House says that severe emotional distress can lead to asymmetric function of the mid-brain. Interruption in the brain-heart coupling could cause the pulmonary edema. He orders Thirteen to load the patient up with diazepam.
Wilson is scrubbing up for surgery when House approaches to tell him that he did drive over to Cuddy's house but did not go in. Wilson reserves judgment and commentary.
Cameron and Chase let Foreman know that Jonah could be suffering from meningitis that he got in daycare. Chase suggests it also could be stomach cancer, leiomyosarcoma. Foreman thinks porphyria is more likely. "Either you can handle both these cases or you can't," Cameron warns him. "If you can't, this is stupid. And dangerous."
Foreman stops by to check on Sophia and finds a bag full of brown urine. Tests show that it was caused by shredded red cells. House asks the team what the girl's homemade furniture looks like. Sawing or burning treated wood releases arsenic into the air and gets absorbed into the internal organs, which is why it did not appear on the blood test. Foreman has the team test her hair for arsenic and then chelate it out of her blood.
Foreman meets Chase outside Jonah's room and reports that there is no cancer or porphyria in the boy. Chase thinks Foreman should ask House for help on the case. Suddenly, Jonah's cardiac alarm sounds. He is flat-lining, but they are able to revive him.
The arsenic treatment works on Sophia but she suddenly seizes. Thirteen, Kutner, and Taub present the new MRI evidence to House. There are several lesions, and the arsenic was helping her. House says to put it back into her system. Taub asks what arsenic treats. The answer is Syphilis and Acute promyeloctytic leukemia. APL explains the lesions, and is why they appeared after they took the arsenic out. Foreman quietly enters the room. Thirteen says that Sophia will need a bone marrow transplant. House tells her to try to convince Sophia to get her parent's bone marrow. Thirteen, Taub and Kutner exit, leaving House with Foreman. House refuses to help Foreman with Jonah's case. They march over to Wilson's office, and House wants Wilson to give his opinion. Wilson doesn't.
Taub and Thirteen prep Sophia for the biopsy. Thirteen finishes adjusting the stereotactic frame onto the girl's head. Sophia would rather die than owe her life to her parents if their bone marrow does match. In order to try to convince her, Taub says that he has Huntington's Disease. This doesn't work. Thirteen is angry that Taub would use her life story. The biopsy confirms APL. Sophia needs a bone marrow transplant. House tells them to run the donor banks. Yet Thirteen wants to track down Sophia's parents because what she wants could kill her. What she needs could save her.
Foreman, Cameron and Chase review Jonah's file. Cameron suggests maybe the mother or brother is causing Munchausen by proxy. Foreman realizes that the boy's brother is the opposite of jealous. He gets an idea and tests Jonah. He has an iron overdose from children's vitamins. Jonah's older brother thought that giving him more vitamins would make him strong.
Thirteen finds Sophia's father and explains the situation. Yet the man is perplexed because his daughter Sophia is home with him. Back at the hospital, Thirteen confronts Sophia about stealing her identity and forging emancipation papers. She needs to get her real parents consent as a minor. Sophia would rather bide her time.
The donor list turned up a partial match. House tells the team to treat Sophia because she must be covering up a trauma worse than rape. House visits Sophia and asks her. He thinks she sees herself as someone who did something terrible who doesn't deserve to live. Sophia confesses that she allowed her brother to die in the bath while she was babysitting him. House persuades her to call her parents.
House is packing up for the night when Foreman enters. He wants to do clinical trials. He proved that he could work two cases at once. House approves because he can't say no if it's not a question.
As House and Wilson are leaving, House looks over to see Cuddy at the desk in the clinic. Wilson notices and tells him he is going to be all right.