Night falls on New Jersey. Dan is asleep in bed, closely monitored via video camera by the extra-hours-working Cottages. House enters Dan's room, which is pretty much all you need to see to know that this is the kid's nightmare, since House would never enter a patient's room in real life. Anyway, NightmareHouse -- who isn't much different than RealityHouse -- restrains Dan and starts putting some rubber gloves on, which is never a good sign. He says that Dan's brain problems are the result of nerve damage in his toes, and starts to mark off an incision point around Dan's big toe. Dan begs to see his parents. As X-Files-style creepy music plays, House picks up some heavy-duty clippers and tells Dan that this is going to hurt. No shit. Dan screams as House cuts off his big toe. Ugh, this is worse than that scene in Misery when Kathy Bates took a sledgehammer to James Caan's feet. And it's still not the most wince-tastic thing that will happen to Dan in this episode.
Meanwhile, in real life, Chase and Foreman stand next to Dan's bed and look at the computer monitor that displays his brain waves. "That's a night terror," Chase says. I guess it wasn't so systemic after all, was it, Chase? I love the guy, but he kinda sucks as a doctor so far.
Dan gets an MRI. Apparently, he comes through it without almost dying, unlike everyone else we've seen get an MRI on this show (which, admittedly, is only one person), and the results, along with his blood work, don't indicate that there's anything wrong. House tells his Cottages to assume that something is wrong, and take a very close look at the MRI. Foreman and Cameron maintain that it looks fine. Chase spots an "meningeal enhancement" and guesses that it's viral meningitis. House says that Chase is very clever to take a guess like that on the assumption that House saw something, but says he is also "pathetic." And wrong. House tells the team to take a close look at the corpus callosum. Chase says it looks "okay." House is outraged, and tells us all what the corpus callosum does: it's the "George Washington Bridge" of the brain, connecting the two hemispheres. He softens his tone and says that the problem is "subtle." Chase says that he sees some "bowing" (pronounced like the bow you tie, not the bow you take). House asks if he's guessing again. Chase says he totally is. House says that, this time, he's right. Chase smirks with pleasure. Hey, even an extremely attractive broken clock is right twice a day. Foreman says that the bowing could be easily explained by the kid's moving during the MRI, which everyone tends to do. Unless, you know, they're dying from an allergic reaction that Chase likes to call "falling asleep." House doubts that Dan was able to shift just one hemisphere of his brain. "There's no tumor," House says, but something is pushing on that corpus callosum. House thinks it's a blockage. "Today night terrors, tomorrow he's bleeding out of his eyes," House says. At this, Cameron winces and looks away. I guess she's squeamish about eyes. House orders a "radionucleotide" (I've seen it spelled "radionuclide," so I don't know if House pronounced it wrong or I just didn't do enough research here) cisternogram, which will show the blockage.