A famous and wheelchair-bound horn player named John Henry Giles plays with a band. By mid-session he loses his breath and passes out from a lack of oxygen.
At the hospital, House wants a piece of the case. He's intrigued that John Henry has been paralyzed for two years without explanation. Cuddy tells House that they're only treating John Henry for pneumonia. The man's paralysis was treated by his primary doctor, Marty Hamilton, in Los Angeles. Foreman did his residency with Dr. Hamilton.
Per Dr. Hamilton's request, House's team starts searching for causes. Hamilton had already diagnosed the paralysis as an effect of ALS, so pneumonia is a possible answer. House doesn't buy this, and seeks other explanations for the paralysis. He suggests an MRI.
As Foreman does up the blood work, John Henry requests a "Do Not Resuscitate" order. Foreman has John Henry put on an IVIG, which later causes him to crash because blood can't get to his lungs. Chase wants to intubate, but Foreman mentions the DNR. House intubates anyway.
Foreman yells at House for saving a patient who chose not to be saved. House reasons that it was the IVIG that caused the reaction, not the disease. Foreman angrily points out that this was House's fault because he suggested the treatment.
House is hit with a restraining order to stay away from John Henry. Criminal charges for battery will be filed. House presses on, ordering Cameron and Chase to consider other possibilities. Cuddy supports House in his case. Yet Foreman has called Dr. Hamilton, who is now flying in from Los Angeles.
In court, the hospital lawyer argues that House has the right to face his accuser. Since John Henry is on life support, the trial will have to wait.
Back at the hospital, Chase sees on the lung biopsy that there is only inflammation. Since House can't order more testing, he begins blind treatment. He suggests starting John Henry on cytoxan, which treats Wegener's disease. If House is right, John Henry will start walking again. If he's wrong, Cameron and Chase could lose their medical licenses.
House is about to administer the cytoxan when Dr. Hamilton shows up. Hamilton, who only calls House by his first name, says that he had initially checked for Wegener's. House reminds Hamilton of the error rate that occurs in those blood tests and biopsies.
Hamilton wants to pull the plug. House tells Wilson that if it is indeed Wegener's, John Henry's lungs won't be able to handle the stress and he'll die.
When he is removed from life support, John Henry starts to breathe on his own. House was wrong about Wegener's disease.
With John Henry's arm now paralyzed, everybody but House is convinced he's stricken with ALS. House asks for more thinking.
The battery charges have been dropped, so House can treat John Henry once again. House visits the patient, who admits that since he can't play the trumpet any more, he doesn't mind dying.
House asks John Henry to just let him find out what's afflicting him. If he still wants to die, House will help make it quick and painless. House puts John Henry into an MRI.
Hamilton offers Foreman a job that pays three times what he now makes and includes many other perks. Foreman mentions the offer to Cameron and Chase, who point out that they don't do this for the money. They also don't hate House like Foreman does.
Looking over John Henry's MRI, Cameron notices sign of a stroke. That would explain the paralyzed arm. Foreman explains the options to John Henry. They can give him heparin to thin his blood and remove the clot, but it could hurt his lungs. Another option is to go in for brain surgery and take the clot out.
Not wanting to risk his lungs, John Henry opts for the surgery. The surgery is a success. John Henry can move his arm following the embolectomy and he feels it when House touches his leg. The doctors are baffled.
Hamilton thinks his ALS treatments are the answer. House thinks they need to take John Henry off the dozen drugs they're currently giving him in order to restart the dosage one by one to see which is having the effect. If not, the toxicity of the useless drugs could kill him.
Hamilton asks House which medications he had been treating John Henry with. House resists, but then realizes that Hamilton needs to know because the patient is worsening. He can't feel his leg anymore. House prescribes steroids and a second MRI.
Meanwhile, House and Foreman discuss their working relationship. House tells Foreman to take the new job if Hamilton is a better doctor.
The MRI results show that John Henry suffers from Arteriovenous Malformation. It was compressing his spine, which caused the paralysis. Foreman wonders how Hamilton could have missed something so simple. House points out that they all missed it too, so something must have been hiding it. It was the inflammation that they first saw on the lung biopsy.
The steroids treated the inflammation and allowed the AVM to show on the MRI. After surgery to remove the AVM, John Henry walks out of the hospital with a simple cane, not a wheelchair.