So Wilson joins the significantly less-fun party, already in progress, and checks out some slides of Ian's blood. He tells them that Ian has no sign of blood cancer and that, even if he did, interferon wouldn't affect him that way. So now we have a kid dying in about two hours and still no clue what he's dying from. Wilson suggests Kawasaki disease, which is shot down because it doesn't affect the elderly like Ester. Wilson doesn't care about Ester; they have one case that seems to fit the symptoms perfectly. Even House has to admit that it looks good, although he lets himself still be right that Ian and Ester are connected by saying that Kawasaki must affect the elderly now. The tests to confirm the disease take too long to perform, so House says that they'll just have to go looking for it in Ian's heart, where it "lives." I also hear that you can find Kawasaki in the garage of someone who wants a bike really bad but doesn't want to pay for something nice.
On the way to Ian's room, Wilson accuses House of going all Captain Ahab on Ester's mystery disease, as he, like Chase, has seen House do this before. "Obsession is dangerous," he warns. House sends him back to his poker game.
While Cameron and Chase do an ultrasound on Ian's heart, his mother asks Foreman if Ester was in pain when she died, since Mom has apparently given up and thinks that dying of multi-system organ failure has a possibility of being pleasant.
Cameron and Chase don't find Kawasaki's in Ian's heart, but they do find a very small mass. This is easy to see, since the real human heart doesn't look anything like that model one in the pre-credits sequence. House checks the mass out and says that Ester didn't get one of those before she died, probably because she was older and died before the disease could progress this far. He wants to do a biopsy on Ian's heart.
House does the procedure himself, which is always fun to see. Except when he sucks out at it like he does this time, hitting the wall of Ian's heart and putting him in cardiac arrest. After, like, ten shocks with the defibrillator -- so many that even Chase the perpetual defib guy asks him how long he's going to keep up this exercise in futility before calling it -- Ian's heart comes back. How stupid do you think they all feel when something like that happens? I wonder if they start thinking about all those other patients they called after only five shocks and whether they could have saved their lives if only they kept zapping them until something good happened. Now that Ian's back among the living, House tries to continue the biopsy, figuring that they might as well, since they're already there. Chase protests that Ian's been oxygen-deprived for eight minutes and probably has brain damage. House doesn't care. As long as he solves that twelve-year-old mystery, he's cool with leaving a dead body and a brain-damaged kid in his wake.