A sweet guy named Andres has Alzheimer's. But before his wife can get him into the risky experimental drug program, he starts vomiting blood. So House's team does its usual round of blind guesswork and treatments that nearly kill him before they discover that he was taking aspirin that his wife was using to feed the plants.
The main interpersonal dynamic is provided by Foreman, who's taking Taub's place on the team. Taub is off with a sick daughter or something, and frankly, I didn't miss him. He just mopes around and that's not nearly as much fun as House sparring with Foreman, who's trying to be the boss while simultaneously help out as House's temporary underling. House has been hiding index cards around the place that are supposed to show his ability to predict the future, but it's all just a complex ploy to get rid of that ankle bracelet that's never really restricted his movements all that much anyway.
And in the side plot, Wilson has a woman with a bladder infection who cheerfully tells him that she and her husband are asexual. House takes that as a challenge and goads Wilson into betting a hundred dollars on his ability to find a medical reason for it. It turns out that the husband has a pituitary tumor repressing his libido and the wife has probably been sneaking out to have the occasional sex. This vaguely ties into the main plot, where Mrs. Andres has a boyfriend.
A woman tells a man, "We're in a car, honey. We're going to a hospital for tests." Then, when they're in the hospital, she tells him they're in a hospital. She's helpful! I appreciate having someone around who's willing to carry all the exposition duties. Eventually, they find themselves in a room where a lady doctor is holding up a can opener. The man is unable to identify it by name, although he knows you use it to "get the food from inside" and then gets angry at her for trying to make him look stupid. He tells the doctor to kill herself and then gets calmed down by his wife, who calls him Andres. He apologizes, explaining that he has Alzheimer's. Well, that would seem to wrap up the week's medical mystery, right? That was easy! Anyway, he's there because he's going to be going on a drug trial. On this show? What could go wrong? Well, for one thing, he starts vomiting blood immediately. Even before the dangerous experimental drugs? This guy's got an awfully sensitive system! Either that or the drugs can travel back in time to affect you before you take them.
House sidles into his office, where Foreman is giving the team the rundown: early-onset familial Alzheimer's, and the client is of Brazilian descent. His only recent issues are a sore throat a few weeks ago. The wife shut down a floral business recently. House is whiny about having to work, naturally, but Foreman says they need to do this case because of the drug test. Foreman will be sitting in because Taub is out with a sick daughter. Good thing they brought that character back, huh? They're doing such rich, interesting things with him. House denied Taub's leave, but only after Foreman approved it. House asks Adams to read the index card taped under her chair. It is a vaguely racist chess-themed prediction that Foreman would start trying to actually act like House's boss. And House got the day wrong. With all that out of the way, Park makes a suggestion about the case. They can't tell if she's right until they take him off anti-emetics to let him vomit freely. Free your vomit, man.
Wilson is in the clinic with a woman who insists she can't possibly be pregnant. Because she's never had sex with her husband. "Neither one of us is interested in sex," she explains. "Celibacy is a choice. This is our orientation." This hospital sure gets a lot of people who can't possibly be pregnant.
Walking through the hallway, Chase pokes at Foreman, telling him he should either overrule House when he disagrees with him or stay out of it entirely. Foreman whines that House griping about Foreman's rule doesn't seem rational, since House needs Foreman to write a petition to his Parole Officer to get the ankle monitor removed.