Emergency responders try to assist a semi-conscious Stewart Nozick. They get him on a gurney but he resists and runs back into his home, barricading himself inside.
House and the team listen to Cameron report on Nozick's illness. He has had agoraphobia for seven years since he was mugged when he was shot and his girlfriend killed. Cameron had contact with the man last year through the Community Outreach program. He has agreed to allow her to come talk to him instead of being admitted to the hospital.
House approaches Cuddy in the hall to discuss that their kiss was a mistake.
Foreman thinks they should provoke a seizure on Nozick to track the increased electrical activity focused around the abnormality. They can do an EEG to see where the problem is. Using portable equipment, the doctors go to Nozick's house. There is a second locked door which he uses as an "air lock" to the outside world. Once inside, the others search for toxins as Cameron examines Nozick in his bedroom y to force a seizure on Nozick.
House is telling Wilson about the kiss with Cuddy when his cell phone rings. Thirteen, Kutner, Taub and Cameron are hovered around a speakerphone. As House talks, he cuts away at his skin over a mosquito bite to release the poison. As Cameron fills him in on the patient, she also must answer questions from House on her relationship with Chase. House insists they recreate the cause of his first seizure.
House shows up at Nozick's with three strangers in order to upset the man. Nozick panics and a seizure is induced. He has pain in his stomach. House asks the team what would cause blockage plus seizures. Thirteen suggests atrial fibrillation throwing emboli. Yet Foreman says there is no way to know without getting him in for an MRI on his head or an exploratory surgery to biopsy his bowels. "Whatever your big problem is has caused a complication we call "colon FOS". He explains that this means his colon is filled with stool, but they need to test his bowel. Nozick refuses to go to the hospital for more tests.
House wants to trick Nozick into believing that surgery will be performed at his house. Instead, House wants Chase to put him under. Then they will secretly take him to the hospital for surgery and return him home before he wakes up.
Wilson joins Cuddy in the cafeteria to chat about what happened with House. Cuddy seems surprised by his matchmaking attitude.
After sedating Nozick, Chase and Cameron push his gurney through the hospital halls. She asks him to stay at her house tonight and they bicker about it. Suddenly they stop short. Cuddy is standing in their way, annoyed. They bring the gurney into an available room to discuss. Do they send him home or keep Nozick in the hospital? House notices that a little blood is seeping out from under the bandaged mosquito bite on his hand.
Cameron awakens Nozick in the hospital and he freaks out. She struggles to hold him down as blood spurts over everything. Cuddy summons them because the patient called his lawyer and has threatened to sue. He's also gone home. She pulls House, Chase and Cameron off the case. After, Cameron asks House what's going on between him and Cuddy. He didn't put up a fight. House tells her to convince the patient to let them in again. House walks off. Chase is amazed that Cameron is still determined even though Nozick is no longer their patient.
Wilson notices that things are weird between House and Cuddy. House argues that emotionally mature people who work together shouldn't date. Wilson says he just wants House to be happy. House wonders if maybe Wilson only wants to live vicariously through him. He reminds Wilson that he was the one who asked out Cuddy last year.
Cameron is able to get through to Nozick, who is clearly in pain. Yet he still won't leave his house. She calls House, saying they need to do it there. House asks Taub to perform the surgery at Nozick's. House and the lawyer watch as Taub cuts a pink piece of bowel and places it in a surgical tray. Kutner gives him a suture. Cameron takes the tray over to a workstation where House has a microscope set up. House examines it as Taub starts to close the patient up. Seeing intestinal atrophy, Cameron realizes Nozick has Whipple's Disease. House smells something but it's too late. Taub sparks the cautery, igniting the built-up gas in Nozick's intestine. Taub jumps back, stunned. House grabs a scalpel and widens the incision, letting the gas escape. The flame goes out. House jokes with Nozick's lawyer to diffuse the situation.
Chase visits Cameron as she tends to the patient at his house. Nozick complains that his legs have become numb. The team calls House in the hospital. Thirteen suggests they run a blood test for celiac but House says to just force-feed the patient wheat, then do an endoscopy as it hits his duodenum to see if there's an allergic reaction.
Wilson comes in to see Cuddy. He makes a feeble attempt at confessing his feelings for her, but Cuddy sees through his ploy. He only wants to make House jealous and come to realize he does want a relationship. She calls Wilson an idiot.
Nozick eats a bowl of cream of wheat to induce a reaction. Cameron quietly encourages him to get help for PTSD but he says he was like this before the shooting. Back at the hospital, House wants Taub to slow the tests down and stop giving him morphine so that the patient will be in so much pain he will be forced to go to the hospital.
House tries to catch the mosquito in his apartment. He misses the bug but knocks out the propane tube of the extermination sprayer in his living room. House looks around and spots the mosquito landing on the stove. He misses again -- but accidentally ignites a burner. House wakes up from this dream and goes to visit Wilson in the middle of the night at Amber's apartment. Wilson thinks there is no bug and that his mosquito bite represents Cuddy. "You got 'bitten' the night you kissed her; your itching always gets worse when you think of her. You need to address this," Wilson insists. He calls House afraid and kicks him out.
Instead of going back to sleep, House goes to Nozick's home where Cameron is napping. He tells her to redo the endoscopy. Cameron realizes that Nozick has no pulse. She performs CPR and House dials Nozick's lawyer without helping her. House gets the lawyer to approve the transfer to the hospital, but Cameron resuscitates the patient and says they are staying.
Taub inserts a temporary pacemaker in Nozick to keep his heart beating. House is sure that the cause must be poison, and he asks the insanely neat patient about cleaning his bathtub with bleach and ammonia which can create chlorine gas. House says to put him on parenteral steroids and sodium bicarbonate.
At the hospital, Cameron asks Chase to put a real pacemaker inside of Nozick. They confront the fact that Cameron made Chase feel like she didn't want him to stay at her place. It is hard for her because she lost her husband. Chase says he won't chase her forever.
Nozick takes a turn for the worse. House tells Cameron to have Taub get real morphine. She admits that she figured House put him the patient on saline, so she switched it back to morphine. She asks if there is something that causes abdominal pain that doesn't respond to morphine. House knows that Nozick is being poisoned.
House goes to the house and examines the bullet entry wound above Nozick's pelvis. It is lead poisoning. Cameron holds Nozick down as House digs into Nozick's abdomen with a scalpel. House removes two metal fragments of a bullet. Yet House then confronts Nozick's claim that he is satisfied with his life. The day he crashed was his girlfriend's birthday. He was heading out to go lay flowers on her grave. House calls him a coward. "If you want to change your life, then do something," he says. "Don't believe your own rationalizations. Don't just lock yourself up and pretend you're happy."
Cameron comes to the hospital to see Chase. She cleaned out a drawer to make space for him.
Nozick stands alone in the entry hallway about to venture out the door.
Taub sleeps on his couch when his wife comes to him. He puts his arms around her and they lie like that.
House drives up on his motorcycle to Cuddy's home. He stops and looks through the window, watching Cuddy for a moment. He decides that he just can't do it. He turns and walks away.