House shows the Cottages Mark's PET brain scans, saying that they tell them everything they need to know. You see, lying takes a lot more brain involvement than telling the truth, and the scan of Mark's brain when he said he and Stacy went to Paris showed minimal involvement, meaning he thinks it really happened. And it didn't.
"DELUSIONS," House writes on the whiteboard in big letters. He thinks Mark has Acute Intermittent Porphyria, which can only be diagnosed when the patient is in the middle of an attack. Chase says that there are other symptoms, like light sensitivity, and House points out that Mark recently gave up the outdoor activity of mountain biking for indoor yoga. He tells them to start Mark on glucose and hematin. Cameron points out that if House is wrong, the hematin will kill Mark immediately, meaning that this time, the guess treatment is more dangerous than doing nothing. They'll need to confirm the diagnosis, but the only way to do that is to get a urine sample during an attack, and there's no way to predict when the attack will happen. "Sure, there is!" says House. Uh oh.
The gang gathers around Mark's bed. House explains that AIP has some very specific triggers that set off an attack. They don't know which of those exactly caused Mark's attacks, so House proposes a "combo plate": an injection of all known triggers that is bound to cause an attack. Stacy points out that triggering an attack will make her husband worse, and House says that's true, but that it will also confirm the diagnosis so that they can treat him. Mark asks what will happen if he doesn't have AIP and they give him the combo plate. "I have no idea," House says. Probably nothing good, though, especially with Mark's brain being so addled. Stacy says she needs a minute with her husband.
House and the Cottages watch from outside. Mark shakes his head. Stacy comes out and says that Mark wants to wait for another explanation. She asks House how much time her husband has. House says they have no idea. The next attack could be fatal, and it could happen anytime. He could die in five minutes or five months. Some genetic test will give them more certain information, but it takes a month. Stacy tells House to give Mark the injection. House won't do anything against his patient's wishes for the first time in the history of ever. Stacy promises not to sue House. He says that's great, but that it doesn't mean Mark won't. Stacy says that if the combo plate doesn't work, Mark will still be paralyzed, and will therefore in no condition to file lawsuits. Hey, go easy on the sympathy, there, Stacy. House says that this is Mark's call, and that he made it. No injection. "You want him to die," Stacy says. It would seem that she hasn't learned ANYTHING from the last time someone she loved made a possibly fatal health choice she disagreed with. House retorts that if Stacy wants someone to tie Mark down and force him to have the treatment she thinks is best, then she can go ahead and do it herself, since she's much better at it than anyone else. Stacy bares her teeth and says that if this is payback for what she did to House's leg, she knows she saved his life, or at least that's what she chooses to believe because it makes her a Noble Hero. "You're gonna kill my husband to teach me a lesson?" she asks. House says that Mark is going to die because Mark is being stubborn, not because of anything House or Stacy did, and Stacy says that House acted the same way when he had his health crisis. Yes, and look how well that turned out for everyone, Stacy. She certainly has a type, though. House says that he respects his patient's decisions. Stacy says that's not true at all; House browbeats them into getting the treatment he knows they need, and the only reason he isn't doing it this time is because he wants Mark to die. And I really don't see how House is doing anything wrong here, and I think Stacy should be telling all of this to her husband instead of giving shit to the guy trying to save his life. Stacy says that when she decided to chop up House's leg, it was just like what he does to his patients all the time. Except that House has a medical license and Stacy does not. And when House does stuff like that, the patient lives and recovers, while when Stacy does it, they have a limp and a Vicodin addiction. "He'll never forgive you," House says, speaking from experience. "Yeah. He will," Stacy shoots back, and walks away. What a bitch! I think I hate her more than Cameron.