Nick, a book editor, makes embarrassingly ruthless comments about his publishing colleagues and the book that they are celebrating. His nose starts to bleed and he collapses.
House and the team discuss Phinaeus Gage, the most famous case study in medical history from 1848. Nick has frontal lobe disinhibition, just like Gage did after he a railroad spike was drilled into his head. Both had an argumentative change of personality. House attributes Nick's issue to alcohol or a brain tumor, and then dismisses the case as boring. The MRI shows nothing, and Thirteen suggests that the tumor may be in another area. House tells them to do a nasal probe.
Nick is in his room with his wife Audrey and their daughter Mika, who has a hearing problem. Taub and Kutner enter to perform the test. Audrey is on the phone organizing fundraisers for breast cancer. Nick starts hurling insults at both her and Taub.
House asks Wilson to go see monster trucks, but Wilson says he isn't interested. Kutner approaches and tells them that Nick's nasal test was clean. House thinks it is brain damage. Foreman and Thirteen administer an MRI to Nick, who is very open about his attraction to Thirteen. When Cuddy enters, Nick is even more aroused. House meets Cuddy in the hallway, and admits to having her come in there to get an ego boost from Nick's honesty.
Foreman and Thirteen find a spot in Nick's anterior cortex that is close to the amygdale, which means he could have Multiple Sclerosis. In the cafeteria, Taub and Kutner complain about Nick's comments. They discuss the notion of a social contract where people engage in false niceties in order to get along in the world. At another table, House asks Wilson why his appointment calendar is blocked off during the monster truck event. Wilson says he is playing racquetball with Taub.
Nick suffers kidney failure, and Foreman reports to the team that Nick is stable on dialysis. They discuss the source. Taub suggests leukemia or diabetes. House presses him about playing racquetball with Wilson. House tells them to test for nerve damage and he wants Taub to check Nick's blood sugar every two hours as punishment for lying to him about Wilson. Kutner tests the daughter Audrey to shed light on her father's problem.
In the middle of the night, as Taub is taking another blood sugar test, Nick confides to him about his frustration with his illness. Taub meets House in the morgue, and House asks him to prove he can play racquetball. Taub gives up and admits he doesn't actually play with Wilson.
Kutner is taking Nick to have a thyroid reuptake scan. Nick insults his daughter, who runs out of the room. Nick starts coughing, his fever spikes and his lungs fill with fluid. The team discusses what kind of infection Nick must have. House instructs Kutner to get a detailed history from the patient. He sends Taub to Wilson.Nick and Audrey's relationship becomes strained by his comments. Kutner reports to House that Audrey takes in stray dogs and perhaps Nick has Weil's.
Taub hands over to House print outs of Wilson's emails. Wilson has a meeting with a doctor at New York Mercy Hospital. After some digging, they wonder if Wilson is either sick or depressed.
Nick starts to improve but Kutner and Foreman explain that his brain damage is too risky. He must cope with this condition of verbal inhibition.
House finds Wilson after he has taken a walk in the cold without a coat on. House insists that he tell him what is going on, but Wilson wants to keep it private and he walks away, angered. Nick is waiting for House in his office and pleads for the brain surgery. House asks Chase to perform it. Something about Nick pushing people away resonates with him.
Chase assists as brain surgeons operate. Wilson joins House in the observation area. House found out that Wilson's brother was living on the street and was brought to the psychiatric ward of New York Mercy, who contacted Wilson. House offers to go with him.
Out of surgery, Nick starts his cruel remarks again. His temperature is dropping while he defends his love to his wife. In the office, the team discuss Nick's hypothermia symptom. House isn't there and is not answering his phone. Thirteen thinks Nick suffers from a hypothalamus problem, and the brain damage is spreading. Foreman orders a full body scan.
At Mercy, Wilson and House learn that Wilson's brother has disappeared. Wilson tells House about how his brother suffers from schizophrenia and he would call Wilson all the time. Once when Wilson didn't take his call, the brother ran away. The guilt that Wilson carries has made him become a people-pleaser.
The team examines the full body scan. Nick has an abdominal aneurism, a lung cyst and density on the liver. They reach House, who has a breakthrough on Nick. Yet this causes House to leave Wilson on his own at Mercy. Nick's glucose was normal, even on steroids, which elevated the blood sugar. The cyst on the lung is Doege-Potter syndrome, where the fibroma secretes human growth hormone and lowers blood glucose levels. His body is having an auto-immune response. House tells the team to remove the fibroma. Nick leaves the hospital and congratulates his wife on her job promotion.
Wilson tells House that seeing his brother proved to be anti-climactic. He invites House to meet him next week. Wilson appreciates that House is honest in his life, but House admits that he could be kinder some of the time. He checks that Wilson really does enjoy watching monster trucks, to which Wilson replies that of course he does.