Now that everyone is sure Melinda got sick from her boyfriend's penicillin sperm even though they haven't so much as checked what medicine Dan actually took or checked in with Melinda about it, they can feel free to release her, telling her parents only that the "set of circumstances" that got Melinda sick won't happen again. Mom understandably wants to know what those circumstances were, and it falls to Cameron to try to figure out a way to deflect those questions, which is never a good place for anyone to be. But fortunately for Cameron and unfortunately for Melinda, Melinda suddenly goes into respiratory distress, sparing Cameron from having to stutter out what was sure to be the worst excuse ever. Foreman and Cameron are about to stick Melinda with the epipen they're sure will cure her until she starts coughing up white sputum and her neck turns blue. Melinda isn't having an allergic reaction this time -- she's having heart failure!
Congestive Heart Failure, to be specific. Now the team, back at the Whiteboard, has to figure out what's causing the heart problems as well as if and/or how they're related to her recent allergic reaction. Foreman wants to assume that Melinda had the allergic reaction to the penicillin sperm and investigate the CHF as a separate incident. He tries to write on the Whiteboard O'Symptoms to clarify his point, but House stops him, telling him that he may not have come up with the name "whiteboard," but that he's all about following its rules. Oh, shut up, House. I mean, why don't they just have him put on a white sheet and a pointy hat and burn a cross on some minority person's lawn already? And then he can make a witty comment about it and we can love him some more and talk about how hot he looked in that tight white sheet. At least this time Foreman gets to get his own back by asking if he can use the BLACK marker, since no one, including House, has any idea what could cause both heart failure and an allergic reaction, which automatically means Foreman was right to focus on just the heart failure. Chase and Cameron find their tongues and provide heart-failure causes while House sits back and ponders.
While Melinda gets an MRI of DOOOM!, Foreman makes fun of Cameron for being a prude about teen sex. At least she isn't writing TV shows that punish sex with horrible painful near-fatal illnesses, though. They do pay attention to their patient long enough to pronounce her heart free of coronary-artery disease.
Foreman tells Melinda this (apparently, her super-overprotective 'round-the-clock monitoring mother went off to get a coffee), and also that they think she either has an infection, or organ-rejection issues that she can look forward to a barrage of tests for. Melinda's brain, apparently compensating for her loss of a working heart and making her intelligent for the first time, figures out that Melinda is probably going to lose her new heart. Foreman assures her that she'll keep her heart for decades of healthy, happy life, which I wouldn't say without knowing for sure that she wasn't in the middle of rejecting it. Melinda informs him that her mother's protectiveness does not extend to the internet, so she's done her research on heart transplants. They only last an average of five to ten years. Oh ho ho! Looks like Foreman was so busy hating on Melinda's mom for "infantilizing" her daughter that he didn't realize that he was doing the same exact thing to her with his overly optimistic outlook! Melinda whines that since she doesn't have much life left in her, she'd like to be doing something better with it than sitting in her sterile bedroom. I agree with this until she says she wants to go to high school, which is probably more of a waste of one's precious life minutes than anything else. I guess the grass is always greener on the other side of the bedroom window, though.