At a disciplinary camp, drillmaster Driscoll put the juvenile offenders through an obstacle course in the pouring rain. Two of them, Park Landon and MacDonald, have problems completing the course. Landon finally falls off a climbing wall and cuts his head. Driscoll berates him further, but then complains of back pains and collapses into the dirt. When he asks for help, Landon just sneers and walks away.
Chase arrives to discover that Taub, Masters, and Foreman are looking at his profile page. He's surprised to discover that there is a nude photo of him, but he notes that someone has reduced the of his genitalia. He offers to show them proof, and they hastily decline. Taub identifies the photo as having been taken at the hotel where the Sanford Wells wedding reception was held. Foreman explains that Chase slept with three women there. House arrives, singing, and tells them about Driscoll's case. He now has bladder as well as back pains. Masters thinks that Driscoll bullies kids for a living and suggests he's using steroids. House dismisses her diagnosis and figures she is again bullying because of issues with her parents. Chase suggests that they test for a mechanical problem with the bladder. House agrees, and then leaves, revealing he's well aware of Chase's new profile photo.
House meets Cuddy in the cafeteria. She has Rachel with her, and Cuddy explains that she is getting a vaccination for Rachel, and it's a requirement for admission to Waldenwood, a first-rate preschool. House looks at Rachel spilling her food and wonders if it's the right place for her.
Foreman and Masters insert a catheter, and Driscoll insists that he has to push the juvenile offenders at the camp. He figures the alternative is more crime and a possible coffin, and defends his success rate. Once they have a sample, Masters and Taub run the test. Chase tells them that the website won't take the photo down, because the hacker put a very small black square on it. He can't shut down his account because the hacker changed his password. Taub asks if any of the three women is a likelier suspect, but Chase admits that he can't even remember their names.
The tests show no infection and indications that the pain is from a nerve problem. Foreman figure that House will go for syphilis since it's a rare, embarrassing disease, and they test. As Masters takes a blood sample, Driscoll grabs her and starts choking her. Back in the conference room, House ignores Masters' injury and returns to differential. The tests prove negative for syphilis, and Masters suggests that one of the camp kids may have poisoned Driscoll with jimson weed or wormwood. House tells them to go to the camp and test, and notes to Masters that when he gave her tough love, she came up with a decent diagnosis.
Chase approaches Sanford Wells and asks if he can identify one of the women so he can hook up with her. The hospital administrator is glad to put him in contact with his niece, Winn, but is less thrilled when Chase asks for the names of the other two women.
House goes to see Wilson and get an idea of how he can cheat on a test that isn't a test. Wilson refuses to give him advice, even after House explains that Rachel is too dumb to get into preschool. However, Wilson can't help pointing out that House cares about Rachel, a charge he angrily refutes.
Foreman and Masters go over the disciplinary camp, and Masters argues that they're treating the symptoms, not the disease of a troubled family. Foreman notes that his brother became a criminal, but she feels that different kids need different treatment. Foreman figures that they should identify the poisoner, and he can identify the poison. They talk to Landon and MacDonald, and Landon claims that he's in for shoplifting, Foreman warns that he'll be charged with second-degree murder if he poisoned Driscoll and the drill instructor dies. However, Landon says that he doesn't have a future either way. Foreman and Masters notice that MacDonald is suffering from allergies, but he refuses to explain why he isn't taking antihistamines.
At the hospital, Masters and Foreman flush Driscoll's system of antihistamines. Driscoll apologizes to Masters, saying that he was taught that a man always owns up to his actions. His heart begins to accelerate and they slow it down. Afterward, the team meets in the conference room, but House is at the preschool playing ground. He notes that they've proven that it's not antihistamine reaction, and they try to diagnose the problem based on the new symptom. Chase gets a call on vibrate, but House tells him to turn it off. When Chase wonders how he knew, House explains that Chase's profile page has changed again, saying that he wants overweight women to call him. Chase runs to the computer while House tells them to take urinary samples and check for a pheo.
At the preschool, House tells the teacher that one of the children was sick, and he can't reveal their name due to doctor-patient confidentiality. He tells her to leave and then starts taking photos of all of the toys.
Foreman leaves Masters alone in the MRI to watch over Driscoll. They talk and Driscoll figures that Landon tried to poison. He admits that he tried to get through to Landon but it's not working. Masters tells him to try telling Landon how he feels, and to understand that the boy never knew his dad and lost his mother when he was younger. Driscoll considers it.
Chase asks Taub to study the expanded photo to see if he can find any clues, so he accuses the correct woman. Taub figures that chase somehow emotionally hurt one of the women, and then checks the camera angles and confirms that the woman who took the photo is short.
When House arrives at Cuddy's home that night, he offers to play with Rachel in her room. Once they're alone, House brings in duplicates of the toys from the preschool and tries to get Rachel to play with them. She refuses and eats the pieces instead.
Chase goes to see the first woman, Winn Phillips, who insists that she didn't take the photo. When he comments on the height, she explains that she tried to take off her heels in the hotel room, but he asked her to keep them on. Winn says that she wasn't mad at what happened at the wedding, and invites him to stay and check out her heels.
Later, Chase tells the others what happened, and that it took him a while to get out. When House arrives, Masters tells him that it's not a pheo, and they realize that Driscoll's condition is getting worse. House figures that Masters is running out of time to validate her own upbringing. They get a page from the ER and discover that someone else has turned up with the same symptoms: Landon.
Taub checks the two patients, who can't think of anything that they have in common that anyone else at the camp would have avoided. Back in differential, the team tries to figure out the link. Chase gets flowers as a thank-you gift from the Wells for his generous donation, and he realizes that the hacker has his credit card. The others suggest Driscoll and Landon were both exposed to Lyme disease, and House orders treatment.
Driscoll and Landon argue about what to watch on the TV. Landon refuses to take the treatment for Lyme, saying he wants to wait and see what happens to Landon. Masters says that she's not trying to break him, and she insists the medicine is the best shot. She leaves the choice up to her, and Landon takes the drug. He starts acting politely, and Driscoll tosses him the TV remote.
House takes Rachel to his office for additional training, and that's where Wilson finds him. He's shocked to see House using a dog clicker, but is surprised to see that it works. House informs him that Cuddy doesn't know what he's doing.
Chase talks to the second girl, Kenzie, the one who he had a threesome with the third girl, Nika. Kenzie is disappointed that Chase didn't call her, but isn't mad. Chase is shocked to discover that she's 17, but Kenzie insists that it isn't her and she doesn't even have online access.
Landon tries to sneak out of the hospital, but Foreman and security stop him. Masters discovers that he stole her car keys. Driscoll cries out and they realize that he's suffering from leg pains. Back in differential, House is busy painting hot sauce on Rachel's toys. Foreman tells them that Driscoll is suffering from kidney failure, which means he doesn't have Lyme disease. House figures that Masters' theory has been proven wrong, despite Masters' objections. He figures that Driscoll changed for some reason other than her speech. Taub suggests botulism that entered the bloodstream. House orders antitoxin for both patients.
As Masters gives the antitoxin, Landon insists that he had to get out. When Driscoll says that he's like the other kids, Landon says that he's never been in trouble with the law. His caseworker sent him there, and Masters asks Driscoll why Landon was there if he wasn't sentenced. Driscoll claims he has no idea why.
Chase goes to see the third woman, Nika. She admits that she's pissed at him, but only because Chase is there and her boyfriend will be back soon. Nika explains that her boyfriend was out of town during the weekend, and shows Chase a photo of him at her sister's birthday. She says that she made a mistake and she wants Chase out.
Masters checks with Landon's caseworker and finds out the truth. She takes Landon out for an antibiotic wash and House sits down next to Driscoll. House explains that he's discovered that the caseworker revealed that Driscoll paid for Landon's enrollment, and he figures that Driscoll is the boy's father. Driscoll asks House not to tell Landon the truth.
Back in differential, Foreman dismisses what they've learned since genetic illness emerges based on age, not time. Chase suggests that something in the environment set off the genetic condition, and then gets an idea about his personal problem. House tells him to sit down, and then suggests heavy metal poisoning brought on by leaking batteries. As chase goes, House heads to the preschool.
As Masters treats Driscoll, the drill instructor says that he can't bring himself to reveal that he's Landon's father, and by the time Landon's mother died, it was too late for him to approach him. Masters tells him that Landon needs a father, not a drill instructor.
House accompanies Cuddy to the preschool to pick up Rachel after her playdate. She's done fine, and the school director says that she may have done a little too well. When she asks if they coached her, Cuddy naturally denies it. House says nothing, and Cuddy asks her daughter if she played with any of the toys. Rachel thinks carefully about it and then says no.
At the clinic, House treats a trucker and talks about how proud he is of Rachel for being an accomplished liar, better than he was at the same age. The patient figures that House is fond of Rachel, but House denies it. As he prepares to give the trucker a local for his injury, House gets a name. He goes to the hospital room and confirms that lidocaine, the local they gave him for his head injury, triggered variegate porphyria. The antihistamines Landon gave Driscoll also triggered the genetic condition. When Landon realizes that he has a shared genetic condition, he becomes suspicious. House says that a liver transplant can cure it, and Driscoll offers to donate half of his liver. When Landon wonders why that would work, Driscoll finally tells him that he's the boy's father.
Chase tracks down the woman responsible for pranking him: Ali, Nika's sister. She explains that she saw what happened, but it has nothing to do with her sister. With some prodding, Chase finally remembers that they talked briefly at the wedding. However, when Ali said that she didn't sleep with men on the first date, he took off. Ali notes that he seemed like a normal guy, and figures that he lost his way, so she provided some negative reinforcement. She gives him his new password and starts to go, and Chase apologizes and invites her to dinner. Ali laughs and refuses.
Driscoll tries to talk to his son, who refuses. Landon assures him that he'll be there for him, as long as he has to wait.
House comes to see Cuddy, who is playing with Rachel. She tells House that the preschool turned down Rachel's application. House assures Cuddy that Rachel is a smart kid, and Rachel climbs up on his lap.