While Taub, Kumar, and Foreman don't see any reason to accompany House and figure out what's going on, Hadley does. She chases House down into Brandon's room (not sure why she had to run to keep up with House, but maybe she had to stop on the way to file for bankruptcy again or something). House tells Brandon that although they found no trace of a brain tumor in his scans, they think there's one in there, and the only way to fix it now is with a risky head-cutting exploratory surgery. Brandon refuses because he knows that they did the head-cutting surgery last week and they never repeat themselves two weeks in a row. Actually, he refuses because he knows his problem isn't a brain tumor, as his reaction to hearing about his possible brain tumor suggests. He wasn't upset or terrified like you'd expect someone who just heard that news would be. And that's because, as House has already figured out, Brandon knows what caused the visual agnosia. "What drugs were you on?" House asks. "His drug tests were clean," Hadley says. Um, way to try to undermine your boss, Hadster. Shut up. House says they were, but they don't test for every drug. For example, if Brandon were supplementing his artist non-income by signing up for drug trials to preserve the illusion to his hot girlfriend (because you only try to keep the hot girlfriends. Ugly ones ain't worth it, apparently) that he's a rich and successful artist, those drugs would not show up on the tox screen. House tells Brandon to admit the truth now while his girlfriend isn't in the room. Brandon does. He says he's been acting as a guinea pig for not one, but THREE pre-FDA-approved drugs. Wow, you only have to do three drug trials to afford a huge loft? Hmmm ...