House

At the clinic, a variety of patients are waiting for treatment. One man, Larry, wants migraine treatment but Thirteen tells him it's not an emergency and he can wait. Foreman approaches her and asks if she wants to participate in his drug tests for potential Huntington's cures. She tells him she isn't interested and admits she isn't doing anything to treat it.

One man, Jason, notices Cuddy's office and sees House inside. He goes in to ask for Dr. Cuddy. House is going through Cuddy's desk and tells him to leave. Jason goes out and takes out a gun. A minute later, House looks up as Jason ushers Thirteen, one nurse, and several patients into the office. Jason demands the best doctor in the hospital or he's going to start killing people.

Jason forces his hostages to barricade the room and draw the blinds. House refuses to back down and notes that taking hostages is unlikely to go well. Jason has his medical files and says he can't breathe, he's tired, he gets skin rashes, palpitations, and insomnia. House wonders if Jason is having marital problems but Jason says he's never been married. House then tries to borrow a match to administer a breath test. House warns Thirteen not to go through Cuddy's desk and one kid, Oliver, provides a lighter. Jason is unable to blow it out held at arm's length. House concludes he has pulmonary scleroderma, and an alkylating agent will solve it. House calls out to ask for propofol to test for scleroderma and Jason demands that Cuddy bring it in, recognizing her from her photo. Cuddy brings in the syringe but Jason tells him to give it someone else. House notes that everyone else is ill but Jason notes that Larry isn't on pain-killers. Larry suggests Jason give the first dose to Thirteen and House notes she's sick. House gives the injection to Larry and nothing happens. However, when House goes to give it to Jason, Larry passes out despite his larger body mass. Jason prepares to shoot House but House warns that Jason needs him. Jason shoots another patient, Mitch, in the leg instead.

Lt. Bowman of Princeton SWAT arrives and takes command. Cameron, Chase, and House's team are working with the patients when House calls them for a differential. He relates Jason's symptoms but a disgusted Chase refuses to participate and walks out. The team comes up with various possibilities but they need to test. House has Foreman and Cameron run tests while Taub and Kutner check Jason's apartment for neurotoxins. When Jason gives out his address, House realizes that Jason has an escape plan. House calls and talks to Bowman to get someone to pick up Jason's blood samples. Jason notices someone outside by the blinds and orders everyone back when he sees SWAT officers outside. House notices that only Jason heard the men, indicating hyperacusus, which indicates nerve damage. He has Jason puff out his cheeks demonstrating left-side nerve weakness, indicating post-herpetic neuralgia. There's a dangerous and painful test that only hurts if the diagnosis is wrong but Jason demands proof and agrees to it. Bowman gets two hostages in return for the medication but is reluctant to send Cuddy in. Cuddy instantly agrees and Bowman wonders if she has a stake in it. Cuddy insists she's okay.

A teenager, Oliver, volunteers to take the shot even though it could cause muscle and nerve damage. House does a quick test and the husband of a pregnant woman, Bill, ends up last. He refuses to take the shot and Thirteen volunteers. House isn't thrilled, noting it's her Huntington's speaking, but she insists and collapses in pain. House then gives Jason the shot while wondering why he's so desperate to find a cure that he takes hostages. Jason suffers the same pain, indicating he doesn't have neuralgia.

Taub and Kutner check Jason's house and Kutner finds a photo of Jason with his mother. Foreman tests and determines there's no blood infection. They're left with a heart condition or cancer. Kutner notes that the photo of Jason's mother suggests either an upper-lobe tumor or adrenal problem. Thirteen notices that Jason has a distended jugular, indicating a heart problem. Jason's pulse is racing and Thirteen says they need paddles. House prepares to do a carotid massage but Jason refuse to let House gets that close, since the paddles will cause his trigger finger to spasm. Thirteen suggests they cardiovert chemically and goes to get the drugs, and House notes Jason can shoot someone else if Thirteen doesn't come back. Jason grabs Oliver and gives Thirteen 30 seconds. House and the hospital nurse, Regina, wonder if Thirteen will come back. Time runs out and Jason prepares to shoot Oliver, but Regina volunteers. He prepares to shoot her and she says Jason needs more time. Thirteen comes just in time but Jason insists that Thirteen take the first dose. House warns it will stop her heart to lethal levels but Thirteen gives herself the injection and collapses. Jason takes the show and House notices he's only sweating on one side of his face: a tumor is pressing on his sympathetic nerves. House concludes he has lung cancer.

House calls Wilson for a consult and they check his throat. Jason displays dry throat, indicating cancer, but he insists on a CRT scan. Jason releases two more hostages in return for a trip to Radiology, then ties Bill, Oliver, Regina, House, and Thirteen around himself and edges to the elevator. Housie still wants to know what drove Jason to get a gun and suggests it was the humiliation of being poked and prodded by doctors. Jason insists that he simply wants an answer.

They get to Radiology and House runs the scan, while insisting there has to be a deeper reason than curiosity. Jason insists it's his life and his body, and there's a truth he'd rather know even if he has to rot in jail. House stops the scan and writes down the problem, then has Thirteen explain to prove they both know the problem and didn't pre-plan things. The scan has a starburst artifact: the metal is messing up the scan. House tells him he'll have to give up the gun to get is scan. Jason threatens him with the gun, and Nurse Regina and Bill run out, explaining that Jason gave up the gun.

House runs the scan and ignores the phone, while Oliver watches. He admits he's curious and it should be safe now. House goes over the scan, ignoring Cuddy and Bowman's attempts to call him, and he's forced to reveal there's no tumor. Jason thanks him but House, curious himself, gives the gun back to Jason to maintain the situation and get the answer.

House finally answers the phone and tells them Jason got the gun back. Thirteen accuses House of being a coward for refusing to accept he can't find the answer, but he accuses her of being a coward for giving up on living. Oliver wants to go but House says they might need him. Outside, Bowman wonders if House is lying but Cuddy disagrees. Bowman starts to set things up for an assault.

House calls the team again and Foreman walks off, realizing Chase was right. The team toss out possibilities and House notices that Jason is now losing hearing in his right ear. Cushing's Syndrome accounts for all the symptoms, even the risk-taking. House calls Cuddy requesting a drug to provoke a respiratory reaction to confirm Cushing's. Bowman refuses to negotiate but Jason releases Oliver and agrees not to test the drugs on Thirteen. Oliver gets out and Cuddy delivers the drugs over. Jason tells House to give it to Thirteen, and admits that he lied to Bowman. He believes that Bowman might have slipped in fake drugs even if House wouldn't. Thirteen injects herself before House can object. Jason asks her how long she has to live and she admits there is no cure. Convinced, Jason takes the injection and admits that at least there was an upside to his risks: she isn't gaining anything. Jason's breathing doesn't change but Thirteen collapses as her kidneys shut down.

House calls his team and Cameron suggests that the various medications Jason has received may be protecting his kidneys. House slaps Jason and spots a twitch, indicating a calcium deficiency. Drugs that cause calcium deficiency also protect the kidneys. House tries to add up all the symptoms and Cameron suggests it's meliodosis. The disease requires exposure in a tropical environmental and the history doesn't indicate that… until Jason admits he's been to Florida. House has the disease but Bowman refuses to give them the cure. Jason offers to release House as a hostage and House realizes Jason plans to give the drug to Thirteen. House volunteers but Jason points out that Thirteen is the one on the same drugs he's been taking. Thirteen tells House to go: either way she'll die.

House walks outside while Thirteen wonders if Jason will feel bad about killing him. He says that she wants to kill herself but needs someone else to do it for her. The SWAT teams move in and plant a frame charge on the wall. Thirteen tries to inject herself but hesitates, saying he has to trust people. Jason prepares to shoot her and Thirteen tries to inject herself… and stops, saying she doesn't want to die. Jason grabs the syringe and injects himself, and the SWAT team blasts themselves in, knocking Jason and Thirteen to the floor. The police haul Jason away and House wonders why Thirteen is still alive. She explains that Jason spared her, and outside Jason and House exchange a look of understanding.

Thirteen begins a one-week regimen of temporary dialysis and Foreman apologizes for leaving the diagnosis. She asks if she can participate in the drug trial.

Cuddy surveys her devastated office when House comes in. He explains the test confirmed meliodosis and she snaps at him, wondering if that's all he cares about. He points out that Jason would have been dead if they hadn't, and she helped him. She wonders if she screwed up because of their non-relationship, and he notes that the only change would be to have a relationship. She wonders if he wants a relationship and he denies it, saying he was just trying to follow her logic. As he leaves, she pulls out the desk drawer and it breaks off: House's prank from earlier finally goes off.