An aging scientist named Ezra Powell begins sweating and gasping for breath. He collapses to the floor.
The next day, House limps into the office with cane in hand. He gives his team the particulars of the latest case. They would rather talk about his cane, but House ignores every attempt to do so. House asks them to focus on Ezra, who cannot breathe. Chase and Foreman immediately recognize Ezra's name from his renowned research. From the file, Chase sees that Ezra's oxygenation has bottomed out and his lungs are full of fluid. He suggests amyloidosis. House would rather put the patient on a treadmill to figure out if the problem is in the heart or in the lungs.
The doctors submit Ezra to the test, but he can't move fast enough to provide real results. As they wait for him, they discuss the return of House's pain and what that means for them. Cameron wonders if there is anything they can do to help. Before she can continue, Ezra has trouble breathing. Unfortunately, his heart rate never got above 90 which renders the test useless. House advises Cameron to drain Ezra's lungs and perform the test again.
Cameron still can't get Ezra's heart rate up even after his lungs were drained of fluid. He is simply too old and weak. House injects epinephrine into Ezra's IV and this causes the heart rate to spike to 130. Nothing turns up on the EKG, meaning that the problem isn't in the heart. House leaves the room and Cameron starts to remove the epinephrine from the IV. Ezra begs her to leave it in. He wants to die.
Cameron informs the team about Ezra's wishes. House and Foreman are greatly opposed to euthanasia, and the others argue about what to do. Suddenly, every pager in the room goes off. The team rushes to Ezra's room, where they find a nurse helping him back into his bed. The nurse found Ezra hanging off the bed with his tubes around his throat. Ezra refuses to consent to any more tests. House tries to force him into a breath test, but Foreman and Cameron stop him. House goes into exact detail about how he will die as his lungs fill with fluid, but Ezra isn't swayed. House asks him for one more day. If he can't figure out what it is in 24 hours, he'll assist Ezra in dying.
The doctors immediately get to work on a battery of tests, rushing to beat the clock. Cameron checks Ezra's laboratory for toxins. The next morning, House casually strolls into the lab and sees that his team has been working all night. He quickly notes a stack of tapes. Cameron explains that Ezra dictates his notes in the lab. House wonders if that indicates that he's losing his memory. He orders an MRI to see if there's a problem with Ezra's brain.
A full day passes and the team comes up with nothing. House lies to Ezra and says that the bone marrow biopsy revealed multiple myeloma. They will need to draw some blood to start treatments. However, Ezra isn't buying it. He knows that none of his tests have shown any indications of myeloma. House begs for more time, but Ezra refuses. There's nothing the team can do but retreat to their offices.
House is deep in thought for hours. Finally, he pulls a leather case from his desk and heads for Ezra's room. The team follows, bewildered. House unfolds the case, pulls out a syringe and vial and orders the team to leave the room. He wants them to make sure somebody sees them in another part of the hospital. Foreman steps in, but House orders him out of the way. Cameron is in tears. Chase draws the blinds. House injects the IV and Ezra goes limp. House quickly grabs the crash cart and asks Chase to help. House gets a laryngoscope and intubates Ezra so they can continue testing him.
House examines Ezra's MRI and notices scarring on the top of his lungs. This, combined with the bad bone marrow, could indicate lupus. Foreman reports that the IVIG made Ezra worse, ruling out lupus. House asks Cameron to return to Ezra's lab and find the January 1967 Massachusetts Medical Journal. There's something in there that she might be interested in. In the meantime, he has Chase biopsy Ezra's lungs and the results are negative.
Cameron reads the article and learns that Ezra once injected newborn babies with radioactive agents just to see if they had urethral reflux. House is confident that Ezra's experiment, which was performed without consent, nicely reflects what he's doing now. If Cameron thinks less of Ezra, she may change her mind and start helping them out. Yet she doesn't bite.
Ezra crashes as the team finishes up the surgery. His right lung has collapsed, so House creates an incision in the chest to relieve pressure. He notices that Ezra reacts to pain stimuli on his left side but not his right. They need to wake Ezra up from his coma to run a somatosensory evoked potentials test to investigate.
House considers Ezra's lack of sensation and orders a skin biopsy. He now suspects Kawasaki's disease, lymphoma and sarcoidosis. The skin sample rules out sarcoidosis, so he throws out amyloidosis. The team counters that it didn't show up in his heart. House presses, and Chase adds it to the stain. The slide immediately changes. The good news is that House was right. The bad news is that it's protein type AA.
House informs Ezra that he has amyloidosis and, with a subtype AA, it is terminal. Ezra congratulates him on a successful diagnosis.
The next morning, Cuddy informs House that Ezra died overnight. The nurse charted that he was stable at 1:00am, but his breathing suddenly stopped at 1:30. Cuddy questions whether House knows anything about that. House asks if she would even want to know the truth.