We go to the Whiteboard of Symptoms, which has become a Transparent Pane of Symptoms, thereby allowing the camera to do some cool rack focuses between the writing on it and the Cottages. Differential Diagnosis Time! House wants to know how a tox screen would turn up negative when the patient is obviously on drugs, which we know because House said so. Maybe the lab screwed up. Maybe the kid took something that the tox screen doesn't test for, like copy machine toner, which has apparently replaced glue as the legal way kids get high these day. Welcome to the new century. House assigns Foreman to go to the kid's house to find his "stash," figuring Foreman would know all the best hiding places. Foreman protests that he's never even taken drugs. You'd think a current drug addict would be better suited to this task, but I guess if the kid's house has stairs, House is pretty much taken out of the running, so to speak. Cameron is sent to make sure Foreman doesn't dip into any of the kid's battery acid or whatever else it is teens like to do these days.
Chase gets to talk to the patient, named Matt. He asks Matt if he did any drugs. "Pencils down," says Matt. Sounds like a new designer street drug to me. Chase tries to ask again, and Mom comes out from the corner she was hiding in to answer for her son that he doesn't take drugs. Chase says that all parents think their kids don't do drugs, and all of them are wrong, except for Foreman's. Mom says she has proof, too: she secretly gave Matt one of those home drug tests, which doesn't really mean anything if Matt is, in fact, ingesting copy toner. "I didn't want him to know," she says, "because I do trust him." Also because, given what we've seen of Matt's test performance thus far, he might have gone into a panic seizure or something. Chase asks how Mom can both trust her son and give him a secret drug test. Mom doesn't have an answer for that. She just says that all Matt did last night was study and argue with her about proper college interview dress attire. She thinks he should dress like a proper gentleman for them, while Matt wants to wear his own clothes and be himself. She still thinks she's right. Matt protests by having a seizure. House watches the action from outside.
Foreman and Cameron spend time in pleasant suburban New Jersey. They search around Matt's room, and Foreman starts talking about House's little remark about how Foreman would know all the best drug stash locations. Cameron exasperatedly asks if Foreman is going to make this a "racial thing," like the guy who said he hired Cameron because she was hot wouldn't do something like that. Foreman says it's actually because House is an addict himself, and that addicts tend to believe that everyone else is an addict, too. Cameron doesn't think House is an addict. Foreman does. They bicker, and get nowhere, so Cameron changes the subject back to Foreman, and incredulously asks if he really never did any drugs. Foreman asks if this is going to become a "racial thing." Cameron says that deflecting tough questions with a joke is something that a certain alleged Vicodin addict would do. Foreman protests that he's nothing like House. Cameron points out that he's wearing the same "gym shoes," like, is Cameron sixty? Who says "gym shoes"?