The Cottages do Jeff's neck scan, even though they know what they're supposed to find there. Chase asks if anyone wants to bet against finding anything at all, but it seems that they've finally learned that you should never bet against the House.
Sure enough, the Cottages return to House's office and say they found a thymoma -- a tumor on the thymus gland -- in Jeff's neck. Thymomas are almost always found in chests, which is why no one considered it when the chest x-rays were clear. Thymomas cause chronic PCRA. Jeff's seemed acute because it came on so suddenly -- as soon as he took a break from those red blood cell transfusion, which were actually only making his red blood count normal, and not artificially high.
House stabs Jeff's leg with a needle. He pronounces Jeff healed. Jeff is understandably skeptical, until his muscles suddenly start feeling stronger. House explains that Jeff's thymoma caused both the PRCA and an autoimmune disease called myasthenia gravis. Both of those conditions combined caused all of Jeff's symptoms, and the treatments both of those conditions -- blood transfusions and a hyperbaric chamber -- were things Jeff was doing anyway, thereby inadvertently curing him until he stopped doing them for the charity race. When Jeff asks him if he fired his manager for no reason, House replies, "Oops." Jeff decides he'd rather keep her 10\% of his Nike contract instead of hiring her back, because he is, after all, a cheating dick. Even House seems disgusted. He says tells Jeff that all they need to do is remove his thymus and he'll be cured. Jeff thought he was already cured. No, says House, he just injected him with Tensilon, something that only temporarily erases MG's symptoms. They should be coming back any time now. Ah, here they are. House watches, amused, as Jeff gasps and falls violently to the floor, probably breaking his head open on the ground. "Clean up on Aisle 3!" House shouts in the direction of the nurse's station.
The next stop on the House version of Sherman's March to the Sea is Stacy's office. She gets all pissy at seeing him, because if there's one thing House is right about in this episode, it's that Stacy is pissy. Even when she's not supposed to be, Sela Ward plays her pissy. She tells House that if he's there to search her office and find out all her personal information, he can go right ahead and start with her purse. But House likes to keep his snooping private, so he declines...for now. He's not there to get under Stacy's skin or gloat that his office was not actually responsible for the press leak. He's there to apologize. Whaaaa? But it's true! He puts on his sincere face and says that they've been punishing each other, and that they can't keep that up if they're going to work together. House wants to know if Stacy hates him or loves him. Either way, they have a problem. Stacy's face shows absolutely no discernible reaction. I really think it would have been cheaper and more dramatically effective if this show had just built a robot for the role of Stacy instead of hiring Sela Ward. Stacy's answer to House's difficult question is that she hates him...and loves him. This is what we call a "non-answer." Stacy says that she loves Mark, too. And she doesn't hate him at all. House doesn't think he and Stacy can work together, but Stacy is sure things will get easier. At least, that's what her therapist tells her. I hope Stacy's therapist gives her the same non-answers Stacy gave House: "It will get easier...and harder. When it's not easy, it will be hard. But when it's not hard, it will be easy. Your forty-five-minute hour is up; three hundred dollars please!" House leaves the office and smiles just a little bit. I thought it was because he was happy that Stacy told him she still loved him, but, as we later discover, it's actually a Smile of Nefarious-Deed Planning.