A mother, Lucille Palmeiro, is hearing voices in her head. She feels a sharp pain in her leg, which turns out to be a blood clot. At the same time, Lucille's son, Luke, is working with a disability counselor to keep his mother's benefit checks coming in. She was diagnosed with schizophrenia last year. The clot moves to the Lucille's lungs and she collapses.
After Lucille is stabilized, a doctor explains her condition to Luke. The doctor is concerned that Luke is giving his mother alcohol, which he claims calms her down. House, overhearing the doctor's lecture, takes an interest in the case.
Why did this 38-year old woman develop a deep vein thrombosis? Dr. Wilson thinks House's only attraction to the case is the schizophrenia. House claims otherwise and drops in on the patient, which shocks Foreman and Chase. During his visit, House learns that Lucille has tremors which prevent her from shaving her legs. She must be bleeding more when she cuts herself. House orders a round of blood work.
Foreman tries to draw blood, but Lucille resists, exclaiming that they're going to steal it. She has to be forcibly restrained. Luke is upset with House for giving his mother Haldol to knock her out. She claims that Haldol makes her soul numb. That night, Lucille begins vomiting huge amounts of blood.
House upbraids Foreman for the dose of Haldol. House wonders if a Vitamin K deficiency explains the delay between the blood test and the vomiting. Foreman and Chase check the patient's home for any unused ampicillin, which was prescribed earlier this year for a sore throat. Foreman finds a strongbox filled with meds, including an untouched bottle of ampicillin. They also find a freezer loaded with microwave burgers. Luke says that's all she eats. House's theory about Vitamin K is becoming stronger.
Chase refuses to believe that the cause is merely a Vitamin K deficiency. He's sticking with alcohol as the cause. Chase and Cameron ultrasound Lucille's liver and find cirrhosis and a cancerous tumor. She needs a transplant because the tumor's size is past surgical guidelines. House suggests injecting ethanol into the tumor to temporarily shrink it so that the surgeon is fooled.
The surgeon operates, but is angry about House falsely shrinking the tumor. Social Services shows up to take Luke away. House starts to wonder if Lucille is actually crazy. That night, House accuses her of calling Social Services so that somebody will take care of her son. House agrees with the call, but that is a sane decision made from self sacrifice, and that doesn't fit in with schizophrenia.
Late that night, House has a revelation and begins calling Lucille's old doctors. They all hang up on him because it's so late. House thinks a specialist made an easy diagnosis. He gathers his team to search for other explanations to her symptoms. Wilson's disease is marked by high copper levels in the body. That does explain the cirrhosis. Seeing that Lucille cancelled an eye exam last year, they give her a quick test. The copper-colored rings around her corneas are a dead giveaway. The doctors start treating her for Wilson's disease.
Within a few days, a perfectly cogent Lucille is happily reunited with Luke. And House takes the blame for the call to Social Services.