A man named Dominic tries to teach his severely autistic son, Adam, to identify shapes and words. Adam doesn't speak and does not have much success identifying the images. Adam begins clutching his chest and screaming frantically.
House is curious about Adam's case. He finds it interesting that, in the ten years of closely caring for their boy who screams frequently, this is the first time the parents have admitted him to the hospital. Foreman and the other doctors simply dismiss the case, citing Adam's severe affliction and his parents' natural overprotective nature. House orders a stool sample to check for parasites, a blood culture to rule out infection and an ANA for lupus.
House barges into Cuddy's office and demands his old, bloodstained carpet which she had replaced. She turns him down. House refuses to use his office.
Foreman and Cameron strap a struggling Adam into a scanner for his first test. The ventilation scan is normal so Adam can be sent home. Yet House wants a fecal smear test. The boys parents tell Foreman that they may have overreacted. Adam begins to gag and cough before spraying mucus out of his mouth. Foreman is now convinced that something is wrong.
Avoiding his own office, House convenes a team meeting in Wilson's office. He orders an echocardiogram and antibiotics if the fluid returns. Adam screams maniacally as Foreman tries to administer the echo. The echo and an EKG confirm a conduction abnormality. Chase, thinking about the effusion, suggests they look for something that explains both the heart and lung problems. House wonders if cancer is present and he calls for a lung biopsy.
Foreman approaches Wilson about Adam's case. There is pleural effusion and conduction abnormality, but an absence of heart failure. He asks Wilson the oncologist if they should perform a lymph node biopsy, and Wilson agrees. During the biopsy, Adam screams once again and the doctors aren't able to hold a gas mask over his face for anesthetization. House comes in and takes a few breaths from the mask himself. This makes Adam accept the mask. He slowly falls under. His parents think it's a miracle that their boy finally had some kind of conversation with somebody. House dismisses it as simple copycat behavior.
Wilson studies the biopsy. He doesn't find cancer, but he does make an astonishing discovery. The cells under Adam's arm are liver cells. The team meets once again in Wilson's office to figure out a possible explanation. House focuses on liver damage, specifically cirrhosis. The team refutes because the echo showed no scarring on the liver and other tests were negative. House theorizes that damaged liver cells -- like cancer cells -- could work their way into the bloodstream and move north. He suggests that perhaps the parents who have been devastated by such a difficult child might have slipped something to him. House wants a liver biopsy to confirm cirrhosis.
Tired of finding House in his office, Wilson corners Cuddy and begs her to put the dirty carpet back. When she refuses, House camps out in her office to discuss Adam's stool sample with Foreman. It had traces of iron, zinc and calcium carbonate. House is intrigued by the carbonate, which is an anti-diarrheal.
Adam is rushed to the cardiac ICU where he must be shocked back to life. His liver is damaged, his heart has abnormal pathways and pleural effusion has compromised his lung function. Yet the biopsy was negative for cirrhosis. House still suspects the parents but notes that Adam has pica, which means he will eat anything put in front of him. House asks Foreman to inspect the home for matches, spiders, mortar and anything suspicious that Adam would put in his mouth.
After a thorough search of the home, Foreman informs House that he found a small patch of Jimson Weed in the backyard. Jimson Weed contains atropine, which is the poor man's acid. It explains the pleural effusion and the arrhythmias. Yet the treatment for that is physostigmine, which doesn't mix with heart issues. They need to be sure before proceeding.
House shows Adam a picture of Jimson Weed and asks if he ate it. Adam instead points to a picture of his sandbox and then his eyes roll back into his head. House presents the new symptom to his team. Foreman wonders if there are tumors, but the team is skeptical that they would have missed that. Foreman plans on performing a CT scan. If that doesn't work, he'll remove the eye.
House sits in Adam's empty hospital room, thinking. When he sees the picture of the sandbox and a chalkboard with wavy lines, something hits him. He rushes to the prep room and calls of Foreman's surgery. House has them darken the room so that he can examine Adam's eyes with a light. Since Adam can't speak normally, he drew squiggly lines over and over again to explain what he was seeing. Worms swimming in his eye. A raccoon used Adam's sandbox for litter and Adam ate what it left behind. The worms spread from his stomach to the rest of his body into the liver, the lungs and the eye. Laser photocoagulation will fix the eye, and a high dose of benzimidazole will kill the worms.
Wilson enters Cuddy's office with a medical textbook. "Asperger's Syndrome is a mild and rare form of Autism. It is typically characterized by difficulty establishing friendships and playing with peers, trouble accepting conventional social rules and they dislike any change in setting or routine," he reads. Cuddy scoffs at the notion that House has Asperger's, but Wilson mentions the fuss over the change in carpet. He theorizes that House took Adam's case because he saw himself in the boy.
Wilson later finds House in the hallway and tells him that he knows he doesn't suffer from Asperger's. He wishes he did because it would free him from any social responsibility. Instead, he has to face the fact that he's simply a jerk. Adam and his parents are leaving the hospital, and Adam stops to give his cherished PSP to House. Adam looks straight at House, making eye contact for the first time in his life.
That night, House watches as a carpenter unrolls his old bloody carpet in his office.