Lucy Palmeiro is at the Department of Employment Development with her son, Luke, asking for an extension of disability benefits. She insults the clerk, Sally, and then complains about pain in her thigh. She then rambles about killing a cat, and Luke informs Sally that his mother has schizophrenia. As he goes through his records and claims that he's 18, Sally tells them that they're all set. Meanwhile, Lucy thinks that the frog paperweight on Sally's desk is talking to her. Sally nervously goes to get a glass of water for her, and Luke asks his mother to hold on. He gives her a small flask of vodka to drink and tells her that the voices aren't real. Lucy clutches at her chest and then collapses to the floor.
House is reading a newspaper in the ER lobby and ducking Cuddy as Dr. Clark talks to Luke and tells him that his mother had a pulmonary embolism brought on by a deep vein thrombosis in her thigh. Luke first lies and claims his dad is late, and then admits he's dead and insists that he takes care of Lucy. Dr. Clark suggests that her condition was aggravated by her drinking. Luke insists that he just gave her vodka to calm her down and she hasn't had any other drink in three days, and she's not an alcoholic. House interrupts and suggests that Clark didn't bother to check Lucy's blood test and is just guessing. Clark quickly offers to refer him the case and House accepts.
House takes the case to his team, and Foreman is unimpressed. Even when House points out that Lucy is 20 years too young to get a DVT and there's no physical trauma, Foreman is unimpressed. House tells the team that Lucy is schizophrenic, but says they can dismiss that as the cause of the DVT. However, afterward, House admits to Wilson that the schizophrenia might be connected to the DVT. He goes to see the patient, surprising Wilson. House asks Luke to leave the room and get him a sandwich so he can talk to Lucy in private, and then asks her how much she really drinks. Outside, Chase and Foreman watch and Foreman wonders why House is so fascinated by a blood clot. Chase figures that House likes crazy people because they're not boring.
Lucy rambles about baseball and House tries to get through to her. He insists that he believes her. Meanwhile, Wilson explains to Foreman that House likes puzzles, but not people. Inside, House tries to get an explanation from Lucy, who insists that she never lies to Luke and makes his life miserable. House comes out and tells the team that Lucy hasn't cut her legs in two months because of the tremors. Since the tremors aren't new, House suspects she's bleeding more and orders blood tests to see why she bled more and stopped cutting. Luke arrives with House's sandwich and House tells him to leave so they can take some tests. House then tells his team to take Lucy off the psych meds. Foreman and Chase go, and Cameron wishes House a happy birthday. He's taken aback that she wished him well and doesn't even know it's his birthday
Lucy refuses to give blood and spits on Foreman. The nurses restrain her and administer a sedative.
House meets with a clinic patient and her mother Terri, and assures Terri that her daughter Wendy doesn't have strep. Terri tries to drag House into a discussion about sugarless cake and getting Wendy to lose weight. House insults Terri about being obsessive and tells her to buy her daughter some ice cream, and then leaves. Luke is waiting for him, and accuses House of giving his mother drugs. House explains that they had to drug her to get the blood test, but Luke begs him not to give it to her.
Luke reads to his mother, who starts coughing. She suddenly starts vomiting up blood and Luke calls for help.
House calls in Foreman, who insists the sedative had nothing to do with the bleeding. Foreman objects, insisting it was a chemical restraint. While they argue, Chase talks to Cameron about how quickly she put together the clotting study. House tells Foreman to go with House's judgment next time and asks the others why Lucy bled out. He informs them that the tests suggests that Foreman might have screwed up, but figures she has a Vitamin K deficiency, a deficiency that causes lack of clotting. Cameron believes an antibiotic reacted to the sedative. Chase suggests alcohol, which accounts for all the symptoms, and says they can ultrasound the liver to confirm. House has them check out Lucy's place so they can confirm before giving a treatment.
Foreman and Chase break into the Palmeiros' apartment and discover that Luke lays out everything for his mother. Foreman finds her medications and confirms that Cameron's' theory is incorrect. They do discover that she eats nothing but frozen hamburgers for meals, apparently confirming House' Vitamin K deficiency.
At the hospital, Luke explains that the hamburgers are all that his mother will eat. House tells him that once they give her Vitamin K, they can send her home. He reluctantly tells Luke that he did the best he could, but Luke insists that as an 18-year-old he should have done better. He admits that he didn't like how Lucy always told him what to do before she got sick, but he misses it. As he puts on his backpack, Luke complains about a pain in his wrist.
Chase is skeptical about the deficiency diagnosis and believes alcoholism is responsible. Foreman realizes he's had someone in a similar situation.
House does an x-ray of Luke's arm and claims he can tell that Luke is only 15. Luke admits the truth and then wants to know how to treat his mother when he takes her home. House warns that he can't handle his duties, and Luke threatens to sue him if House reveals privileged information. House tells him to relax and admits that it isn't Luke's x-ray.
Chase and Cameron do an ultrasound of the liver and discover that she has cirrhosis. However, they also find a tumor and realize she has cancer. They take it to Wilson, who explains that the tumor caused the bleed. they break the news to Lucy and Luke. Lucy watches as Luke tries to deal with the news that his mother is dying.
Back in differential, Cameron points out that Lucy needs a donor liver, but House warns that it won't happen given her mental issues. Surgery to resect the tumor is the next option, but it's too large. House wonders if they can claim the tumor is shrinking. Wilson gives her ethanol, which dehydrates the tumor cells and shrinks it temporarily, putting it within surgical guidelines.
Cuddy comes to see House and tells him that she knows what House did. He initially thinks she's talking about the ethanol, but then realizes she's bluffing. However, Cuddy figures there' something there. House lies and claims he figures Cameron came to Cuddy about his birthday, and he didn't want anyone to make a big deal out of it.. She backs off and says she was just going to remind him he owes clinic duty... and then gets all of House's patient charts.
At the clinic, House meets with a compulsively hiccupping patient who has tried hitting himself. House has him demonstrate, and Cuddy comes in and insists on meeting with him. He goes to the men's restroom and Cuddy comes in after him. She demands to know how Lucy's tumor shrunk, and knows he requisitioned ethanol. House insists he was concerned about Lucy and stands by his actions.
Cameron comes to see House and wonders if he really didn't know it was his birthday. He admits he didn't, and wonders why she's there. Cameron claims to only be there waiting for the surgery, and he tells her to go scrub in.
Bergin performs the operation but quickly realizes that House used ethanol to shrink the tumor. He tells Cameron to warn House that he won't do it again. Afterward, Luke writes down Chase's advice, and Chase tells him to relax because there are some thing that just can't be fixed. Luke wonders if Chase would give up, and Chase admits he wouldn't. Trina Wyatt with Child Services arrives and knows that Luke is 15. She insists that he come with her to be housed at Child Services. Luke tells Lucy that he loves her, and then reluctantly goes, walking past House and calling him a bastard for calling Child Services. As he leaves, House gets an idea and realizes that Lucy isn't crazy.
House takes Luke's place and reads to Lucy, then wakes her up. He tells her that she called Child Services and she initially denies it. House figures that she wanted someone to take care of Luke for once, and checked the phone records to confirm she made the call. He leaves and talks to Wilson, insisting that self-sacrifice isn't a symptom of schizophrenia. House figures that she got a misdiagnosis initially and the other psychiatrists perpetuated it.
At home that night, House plays the piano to help him think. He takes a drink and then gets an idea. After reading Luke's notes, House calls a Dr. Jeffrey Walters at 3 in the morning. Walters hangs up and House calls again, claiming he's a doctor in London. That doesn't work, either. House goes back to the hospital and calls in the team, and explains that the psychiatrists diagnoses Lucy as schizophrenic because they deal in mental illness and interpreted her disease that way. He has them focus on a disease that would present psych symptoms, and Cameron suggests Wilson's Disease, caused by an accumulation of copper . Foreman points out that House just wants to find a cure, but House persists. He notes that Lucy cancelled all of her appointments after meeting with an onthamologist. Wilson's presents with cataracts and cirrhosis.
House goes to see Lucy and tells her that she's not crazy. They do an eye scan and determine that she has copper deposits in her eyes, confirming the diagnosis. They treat and she soon recovers. Luke is released and comes to take her home, and she assures him that she's fine. As they leave, they meet House and Wilson in the elevator. Lucy thanks House, and Luke still blames House for calling him in. House tells him that Cuddy called Child Services. Once the Palmeiros go, House admits that Lucy isn't as interesting now that she's sane, and Wilson wonders if it's House's birthday.