Plot

Drag racer

Drag racing

Drag racing is a competition in which specially prepared automobiles or motorcycles compete two at a time to be the first to cross a set finish line, from a standing start, in a straight line, over a measured distance, most commonly a ¼-mile straight track....

 Casey Alfonso experiences blurred vision and distorted hearing after she develops a seizure

Seizure

An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

 following a race. Sent to Princeton-Plainsboro Teaching Hospital, House

Gregory House

Gregory House, M.D., or simply referred to as House, is a fictional antihero and title character of the American television series House, played by Hugh Laurie. He is the Chief of Diagnostic Medicine at the fictional Princeton-Plainsboro Teaching Hospital, where he leads a team of diagnosticians...

 takes the case, hoping that by solving it, he will be able to test drive a dragster

Drag racing

Drag racing is a competition in which specially prepared automobiles or motorcycles compete two at a time to be the first to cross a set finish line, from a standing start, in a straight line, over a measured distance, most commonly a ¼-mile straight track....

, but Foreman

Eric Foreman

Eric Foreman, M.D., is a fictional character on the Fox medical drama House. He is portrayed by Omar Epps.-Background:A neurologist, Foreman was a member of Dr. Gregory House's handpicked team of specialists at Princeton-Plainsboro Teaching Hospital's Diagnostic Medicine Department...

 does not believe her symptoms are life-threatening, suggesting she is simply suffering from heatstroke. When an agent from the CIA

Central Intelligence Agency

The Central Intelligence Agency is a civilian intelligence agency of the United States government. It is an executive agency and reports directly to the Director of National Intelligence, responsible for providing national security intelligence assessment to senior United States policymakers...

 recruits House to help diagnose a mortally ill agent named "John", House puts Foreman in charge of the fellowship candidates and the case. Foreman reiterates his heatstroke diagnosis to Casey, until she suffers a second seizure and a vertical nystagmus. The case becomes more frustrating and impatient for Casey when she develops a high fever, following the team's suggestion of Miller Fisher syndrome.

At a CIA-designated hospital, House meets Samira Terzi, who is spearheading John's case, and immunologist

Immunology

Immunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. It deals with the physiological functioning of the immune system in states of both health and diseases; malfunctions of the immune system in immunological disorders ; the...

 Sidney Curtis from the Mayo Clinic

Mayo Clinic

Mayo Clinic is a not-for-profit medical practice and medical research group specializing in treating difficult patients . Patients are referred to Mayo Clinic from across the U.S. and the world, and it is known for innovative and effective treatments. Mayo Clinic is known for being at the top of...

 as a secondary consult. The only information Terzi gives to both doctors is that John was stationed in Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

 during most of the year and liked to eat chestnut

Chestnut

Chestnut , some species called chinkapin or chinquapin, is a genus of eight or nine species of deciduous trees and shrubs in the beech family Fagaceae, native to temperate regions of the Northern Hemisphere. The name also refers to the edible nuts they produce.-Species:The chestnut belongs to the...

s. When House and Curtis meet him, he is cachectic

Cachexia

Cachexia or wasting syndrome is loss of weight, muscle atrophy, fatigue, weakness, and significant loss of appetite in someone who is not actively trying to lose weight...

, has peeling skin and deformed fingernails. Curtis initially suggests horse-chestnut poisoning, but House dismisses this as horse-chestnuts are foul-tasting and impossible to confuse with edible chestnuts. Other diagnoses include alcohol-induced pancreatitis

Pancreatitis

Pancreatitis is inflammation of the pancreas. It occurs when pancreatic enzymes that digest food are activated in the pancreas instead of the small intestine. It may be acute – beginning suddenly and lasting a few days, or chronic – occurring over many years...

 and radiation poisoning

Radiation poisoning

Acute radiation syndrome also known as radiation poisoning, radiation sickness or radiation toxicity, is a constellation of health effects which occur within several months of exposure to high amounts of ionizing radiation...

, resulting in them treating for the latter. However, House secretly stops treatment for radiation and switches to that for pancreatitis. When John becomes unresponsive and almost comatose

Coma

In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...

, House suspects Waldenström's

Waldenström macroglobulinemia

Waldenström's macroglobulinemia is cancer involving a subtype of white blood cells called lymphocytes. The main attributing antibody is Immunoglobulin M . WM is an "indolent lymphoma,"...

 and John is treated with plasmapheresis

Plasmapheresis

Plasmapheresis is the removal, treatment, and return of blood plasma from blood circulation. It is thus an extracorporeal therapy...

 and chemotherapy

Chemotherapy

Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....

. Unfortunately, his hair falls out too quickly to be a side effect of the chemotherapy, and House believes John was the target of an assassination attempt.

Back at Princeton-Plainsboro, Foreman believes his patient has multiple sclerosis

Multiple sclerosis

Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...

, following a string of tests the candidates conduct and begins the treatment of interferon

Interferon

Interferons are proteins made and released by host cells in response to the presence of pathogens—such as viruses, bacteria, or parasites—or tumor cells. They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.IFNs belong to...

, until Casey develops leg paralysis, due to Chris Taub

Chris Taub

Christopher Michael "Chris" Taub, M.D., is a fictional character on the Fox medical drama House. He is portrayed by Peter Jacobson. He becomes a member of House's new diagnostic team in the Season 4 episode titled "Games".-Professional life:...

 and Amber putting her on steroids at the same time, deducing instead that it is lupus

Systemic lupus erythematosus

Systemic lupus erythematosus , often abbreviated to SLE or lupus, is a systemic autoimmune disease that can affect any part of the body. As occurs in other autoimmune diseases, the immune system attacks the body's cells and tissue, resulting in inflammation and tissue damage...

. Taub

Chris Taub

Christopher Michael "Chris" Taub, M.D., is a fictional character on the Fox medical drama House. He is portrayed by Peter Jacobson. He becomes a member of House's new diagnostic team in the Season 4 episode titled "Games".-Professional life:...

 suspects botulism

Botulism

Botulism also known as botulinus intoxication is a rare but serious paralytic illness caused by botulinum toxin which is metabolic waste produced under anaerobic conditions by the bacterium Clostridium botulinum, and affecting a wide range of mammals, birds and fish...

, given the speed of the symptoms, but Brennan strongly feels it is polio

Poliomyelitis

Poliomyelitis, often called polio or infantile paralysis, is an acute viral infectious disease spread from person to person, primarily via the fecal-oral route...

. His suggestion is immediately turned down, until Brennan returns with positive test results for the condition. Although the team is downhearted because of the test result, Brennan suggests a treatment of vitamin C

Vitamin C

Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...

, which he believes can destroy the polio virus (a therapy tested inconclusively in the 1950s) and restore Casey's use of her legs. She improves significantly, however, Foreman notes the inconsistencies of the bloodwork: when Casey was brought in, her blood was negative for polio.

Curtis blasts House for misdiagnosing John, and due to the bone marrow damage caused by the radiation treatment, he does not have long to live, but House remains adamant in solving the case and suggests a herbal treatment called cordyceps sinensis to restore the damage. While House is sitting at his bedside, John tells him of his time in Bolivia, but House realizes John was not in that country, but Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, having eaten large quantities of Brazil nut

Brazil Nut

The Brazil nut is a South American tree in the family Lecythidaceae, and also the name of the tree's commercially harvested edible seed.- Order :...

s that naturally contain selenium

Selenium

Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...

. House informs Terzi and the agent, putting John in chelation therapy

Chelation therapy

Chelation therapy is the administration of chelating agents to remove heavy metals from the body. For the most common forms of heavy metal intoxication—those involving lead, arsenic or mercury—the standard of care in the United States dictates the use of dimercaptosuccinic acid...

; although the agent does not see why House is angry if the treatment is successful even with imprecise information, Terzi realizes that by not disclosing it sooner, the agent did not do what was needed to save the patient from the beginning.

Back at Princeton-Plainsboro Hospital, Foreman shows House the inconsistencies involving Casey, and House suggests her symptoms fit either because she has polio, or because someone poisoned her with thallium

Thallium

Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray poor metal resembles tin but discolors when exposed to air. The two chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861 by the newly developed method of flame spectroscopy...

which yielded a false positive for the polio test. The fault lies on Brennan, who admits to the scam, saying it was necessary to prove the vitamin C treatment was reliable and a possible cure for the virus, thus promoting its discontinued research. House does not fire Brennan because he did what he believed, but he tells him to quit instead, stating he is ethically insane, while notifying Foreman to call the authorities. After expressing apparent anger with the question, "Who the hell did I leave in charge?" and getting his answer, House tells the candidates there's a reason Foreman is in charge — he knows what he's doing.

Later, Cuddy confronts House about his whereabouts, Houses says he was at a 'Rich guy house in Long Island helping his son with the sniffles', Cuddy doesn't believe this and tells House to do his clinic hours and Wilson's 16 hours. Outside, Terzi states she wants to take up House's offer of a job and says she'll be in 'Monday 9 o' clock'.