A female Air Force pilot named Greta flies a Stealth fighter jet with precision over a desert landscape. She begins to perceive sounds for the flight rather than visuals. She heads for a crash into the mountainside. Greta is actually in a virtual reality flight simulator inside a warehouse. Angry and confused, she blames the controller for her crash.
In the hospital lecture hall, House asks the Fellowship candidates to identify the man on the screen behind him. It is the actor Buddy Ebsen, who was diagnosed with an allergy to aluminum dust in the make-up used on him as the original Tin Man character in "The Wizard of Oz." House dismisses the group to investigate the allergy. Cuddy comes to the door to tell House he'd better start eliminating candidates. House proceeds to fire the entire Row C. Yet when a pretty applicant goes to leave, House changes it to Row D instead.
House gets a page from his own pager number. He enters his office to find Greta waiting. She offers him fifty thousand dollars in cash to diagnose what is wrong with her. It appears that she is seeing with her ears, and she hopes to keep this fact from NASA and the Air Force where she is a candidate for astronaut training.
House brings the case of synesthesia to the remaining group of applicants and tells them to keep it a secret. He assigns some candidates to perform different tests on the patient. Another group is sent to break into Greta's home to find out what she is hiding. He tells the rest of the candidates to wash his car.
While candidate Jeffery Cole washes House's car, the others assigned to it complain. Amber Volakis has them all stop, and she takes the car to a carwash with Cole.
The trio designated to break into the patient's home also complain. Henry Dobson, a candidate far older than the others, manages to break into the apartment and outsmarts his younger colleagues.
Candidates Taub, Jody and "Thirteen" report back to House that the patient has an elevated red blood count. A group of doctors walk past House's office and he notices that one looks very much like Chase. House decides that the cause of Greta's problem must be carbon monoxide poisoning from her fireplace.
When Amber returns from the carwash, House has her put the patient into a hyperbaric chamber. In the chamber, Greta suffers a heart attack from the oxygen therapy. The doctors try different methods to save her. When they hit her with defibrillator paddles, Greta is set on fire.
House asks the doctors what could have caused the heart attack. Henry suggests a cardiomyopathy, and House tells him to do a transesophageal echo. He orders the rest to go document ten things that cause infection in the hospital cafeteria. House tells Wilson that he saw Chase. Wilson thinks it's only an illusion, and he attributes it to House's guilt because Chase and Cameron are in Arizona.
Henry hesitates inserting the endoscope into Greta and gives it to Thirteen to do instead. The Fellows follow House down the hallway to update him. He recommends a test for hyperthyroidism. While candidate Chris Taub administers the test, the patient has a panicked reaction when she finds out that they had been to her home. Greta runs out of the room and locks herself in the hospital chapel. As the Fellows try to reason with her, House arrives. He notices someone who looks like Cameron but with blonde hair. Cuddy comes upon House to ask the identity of the mystery patient in her hospital. She admonishes him about running everything past her.
House checks in with the team, and they decide that the patient suffers from liver cancer. House asks Wilson for advice on how to test Greta. Lawrence Kutner, who was eliminated as number 6 has returned with his number upside down as a 9. Kutner provides the answer: they should get Greta drunk and measure her response. House chooses Cole, a Mormon who does not drink alcohol, to be the control group.
While feeding Greta shots of tequila, House thinks that he sees Forman walk by. He chases him down the hall. By the time House returns to Greta's room, she has disappeared. Cuddy chastises House for the unorthodox tests he is doing. She takes a whiff of him and asks if he has been drinking.
With Cole and Thirteen, House examines Greta's belabored breathing and concludes that she has lung cancer. Greta refuses surgery, fearing that NASA will see the scars it will cause. House consults the Fellows. Since Taub is a plastic surgeon, he suggests breast implant surgery to mask the scars. Prior to surgery, Cuddy asks House to explain why the patient is undergoing cosmetic surgery. He says it is in the best interest of the patient.
During the surgery, the team finds cysts on Greta's lungs. House calls out to the doctors for a diagnosis. He hears someone in the viewing gallery give the correct answer -- Von Hippel-Lindau Syndrome. That person is Chase. House is unsure if this is another vision but then realizes it is not. Chase has joined the surgical staff of the hospital and he was really in the hall.
House confronts Wilson who knew all along that Chase returned from Arizona. Cameron now works downstairs in the emergency room of Princeton-Plainsboro. Forman is at New York Mercy Hospital.
Greta awakes from surgery and still insists on not telling NASA. House lets her know that he told NASA himself.
House is in front of the candidates in the lecture hall and announces his selections. In the hallway, he addresses the eldest candidate, Henry. House says that he knows Henry did not attend medical school. He offers him the position of assistant.
House approaches Cameron in the ER. He says that he had lied about telling NASA of Greta's condition. He couldn't kill her dream.