In the lab, Chase says whatever he's looking at under the microscope isn't MRSA. He and Taub try to guess what it could be instead, and then Taub laughs at Chase for seeming to buy into Sir William's theory that he does the knight thing for fun and to prove bravery. "You would say that," Chase scoffs. He doesn't think Taub has ever won a fight. "I took on three guys in college once," Taub starts. Seriously -- never doubt that the little man can fight. He always has something to prove. But we won't hear any more about that, as House enters and tries to act superior to his underlings, which soon falls apart when he's forced to reveal what Sir William's rash really is and how he knows it: it's just poison ivy, and House has a similar rash on his arm where he handled Sir William's sword. Ha ha! That's why you shouldn't touch other men's swords. You don't know where they've been. House says a severe reaction to poison ivy could explain Sir William's eyeball hemorrhages, and if he breathed it in through bonfire smoke (a bonfire consisting entirely of poison ivy plants, apparently. That probably wasn't a good idea), it could have created havoc with his lungs and sinuses, causing everything else. Hmmm. I've never had poison ivy myself, but my best friend Brenda was really sensitive to it, so every summer she'd get it everywhere if she so much as looked at a poison ivy plant. She got it in her eyes and I think she got it in her lungs one year, or at the very least inside her mouth. But it was nothing like they're suggesting Sir William's reaction to poison ivy is. And then all the pagers go off, indicating that Sir William has taken a turn for the worse.