Father Danny is only mildly annoyed that he's being treated for something he doesn't think he has. If I knew I didn't have AIDS, I'd refuse to let them give me drugs for it. Suddenly, his BP starts to climb. He rips his gown open to reveal lesions all over his chest.
House puts the lesions on the Whiteboard over Taub's objections that they're just a reaction to the AIDS medicine. Meanwhile, Foreman and Hadley are both in the meeting room wearing their frowny faces. House diagnoses Danny with hyper IgE syndrome, also known as Job's syndrome. None of the symptoms line up with it, but it's just too perfect for House to resist. Kumar turns that down and Hadley suggests cerebral microtumors. Foreman scoffs that they didn't see any tumors in the scans, and Hadley spits back that's why she called them "micro." They fight a lot and House watches, still eating this up. "This isn't going to work," Hadley says. House disagrees: "conflict breeds creativity." The writers of this show must be having a love-in, then. House orders Kumar to run some genetic tests.
Taub is quick to tell Danny that he still believes he has the AIDS. Then Taub shits his pants because Ryan just showed up. Oh, you are so fired, Taub. Now that Foreman has his job back, you are that much less necessary. Taub runs over to Ryan and panics that he shouldn't be here and it's not a good idea for him to speak to Danny. Danny's up for visitors, though, so Ryan walks up with an angry look on his face that quickly changes to remorse. "I'm sorry," he says; "for everything." Taub's jaw drops slightly. See, Taub? You were wrong. Stick to your own religion; these Catholics are too hard to figure out. Ryan kneels at Danny's bedside, and Danny tearfully puts his hand on Ryan's head (not the head that would get him in trouble, though) and says "I know." He's been waiting four years for this moment.
Wilson drops by the meeting room for plot-furthering purposes. House stares at the Whiteboard and ignores him as he tries to convince House to overlook Cuddy's hypocrisy and attend the ceremony. In doing so, he gives House his epiphany. He erases "hallucination" from the Whiteboard over Wilson's objections. Without it, he's got his diagnosis. Wilson says he can't just eliminate symptoms because they don't fit his diagnosis. House says he can if it isn't a symptom.