Damien and Julia are making out in a hotel when there's a knock on the door. It's the woman's husband, Tom. She runs to the hotel door and Tom has the school papers for their daughter, Evelyn. He doesn't seem surprised to see Damien and introduces himself. He leaves them to it and goes. However, once he leaves, Julia complains of stomach pains and collapses on the bed in pain as Damien goes after Tom.
As Sam and Wilson have breakfast at the condo, he suggests that she leave some clothing there. House comes in and acts politely toward her. However, once Sam leaves, House tries to undermine Sam again and warns that it'll go bad again. He notes that Sam leaves the milk in the door of the refrigerator, which Wilson hates.
In differential, Thirteen tells House about Julia's case, and tries to pique his interest by saying she's in an open marriage. Taub doesn't believe that a happy open marriage exists, and Chase would rather focus on the intestinal blockage. They speculate she got it from one of her partners, and Foreman suggests herpes. House agrees to a barium dye test and goes to administer it himself. He meets with Julia and Tom, who appear happy. Once Tom leave, Julia explains that Evelyn is six and knows all about their open relationship. House is skeptical but Julia insists that it works best for their relationship to be honest.
Taub is flirting with a nurse, Maya, when Thirteen comes by. He claims Maya is just a friend, but Thirteen doesn't believe it and warns that it's dangerous. Taub insists that nothing is going to happen. They get the x-ray, which shows no blockage, but House wants to keep testing. He tells Taub to stay overnight to administer all the tests and find out more about the couple's open marriage.
At home, Wilson and Sam are doing dishes. He notices she put in a dish the wrong way, glowers briefly, and then goes on without saying anything.
Taub talks to Julia about her wedding, and she explains that after three years, they realized they were miserable. Julia's heart starts racing and Taub calls in a crash cart. Once they revive her, Chase asks for a list of sexual partners from Tom, explaining that she probably has a parasitical infection and either one of them could have picked up something from a partner. However, Tom explains that he doesn't have any other partners and he hasn't been any further away than Nebraska. He has an open marriage to make Julia happy. When Chase tells House, House doesn't believe that Tom cares about Julia's feelings. Thirteen figures that House is trying to find a flaw because he believes in monogamy, but House denies it. Thirteen has confirmed that Julia has been with two men and both of them haven't left the country. House concludes that Tom is lying about going to Nebraska.
As Chase and Thirteen go to check out the couple's apartment, they discuss the open marriage and Thirteen explains that her father was having an affair even while he tended to his dying wife for two years. Chase finds receipts confirming Tom was in Nebraska, but Thirteen finds an imported luffa.
That night, Taub has dinner with his wife Rachel and explains what they found. When he brings up the couple's open marriage, she points out he doesn't usually talk about his patients, and asks if he wants an open marriage. Taub denies it but she doesn't believe him and figure there's someone else. Finally he explains that there is a woman at the hospital that he finds attractive, but insists nothing will ever happen. Rachel says that being married to him is enough for her, and wonders if he feels the same. Taub insists he feels the same, but then receives a call that Julia's legs are paralyzed. Rachel wants him to stay and talk, but he goes to deal with it instead.
Tests show nothing that caused the paralysis, or any evidence of a parasitical infection. House notices that Taub scratched himself with a lousy razor that he got at work because he stayed there instead of going home. Taub admits that he proposed open marriage to Rachel, and because House pushed him to do it. House figures he was doing him a favor, whether it turned out good or bad. Chase and Foreman focus on the case and suggest that increased libido between the couple suggests adrenocortical carcinoma. House orders a MRI of Julia's adrenal glands to confirm the theory.
At home, Sam continues to irritate Wilson with little things like throwing bananas in the garbage. She points out that she hates bananas and Wilson realizes that it must be House. However, when he talks about the milk, she isn't convinced that it's all House. Wilson tries to drop it, but she asks if he had a list of annoyances when they were married.
Tom brings Evelyn to see Julia. They're interrupted when Damien comes in, and Tom tells him it isn't a good time. Julia asks Thirteen to get Evelyn out, and Tom then orders Damien out. Julia agrees and Damien takes offense. He leaves, disappointed.
Wilson starts going over the list of his annoyance and he and Sam are soon fighting.
As they test Julia, Thirteen discusses Taub's apparent genetic predisposition toward cheating, and suggests that his problem is denying it. Taub insists he's going to keep trying with Rachel. Thirteen notices something on Julia's lung.
Wilson and Sam continue to argue, and Sam accuses him of lack of emotions. He finally calls her a selfish bitch.
Thirteen tells House that they found a clot, but now they wonder what kind of clotting disorder it is. Cuddy arrives and tells House that Julia and Tom don't have insurance because it lapsed due to non-payment. House goes to see Julia and Tom, and Tom admits that they're behind on the premiums and he's been using his retirement account to cover the expenses. Julia didn't now about it, and Tom admits that he lost all of their savings.
Thirteen gives heparin for the clotting, but House wants to figure out how the new information accounts for the symptoms. Wilson comes in and tells House that Sam has broken off their relationship. House denies that he feels responsible, and says that he just wanted Wilson to stand up for himself. Wilson would be happy with Sam, and leaves when House asks him out to dinner.
As Thirteen tests Julia for clotting disorders, Julia says that she sent Tom home because he lied to her. She talks about how she inadvertently ended up with another woman's husband without knowing he was married. She felt superior because she knew her marriage wasn't like that.
Taub comes home and Rachel tells him that when he had his affair, it wasn't the sex. It was his lying about it. Rachel then tells him that he can have his affair as long as he keeps it to one night a week and he's home by midnight. Taub insists that he wants her, but Rachel notes that he wants more than her. She loves him and believes that he loves her, but he needs the thrill, so she's willing to accept him as he is.
All of the tests for clotting disorder come back negative. House sniffs at Taub, notices his cologne, and realizes that Rachel gave him permission to sleep with another woman. Thirteen and Foreman are shocked, House is intrigued, and Chase doesn't care. They're interrupted when they get a page: Julia is having stomach pains. The exam and ultrasounds show nothing, and the team wonders what caused a resurgence of the pains. Taub suggests that something caused the pain to stop during the x-ray… and the barium enema House gave her beforehand. They realize that her bowel has turned in on itself, cutting off blood flow, and they have to fix it before it turns necrotic. It indicates cancer, and they'll search her abdomen for tumors.
Cuddy comes into her office and discovers that House is there and has bought her an espresso machine. House explains that he did something nice and karma works, so he's being nice to Cuddy in the hopes of either oral sex or Lucas dying.
As they operate on Julia, Chase suggests that Rachel might be going out to see someone. Taub doesn't believe it but insists he can handle it if she does. Afterward, they report to House that they discovered non-specific inflammation suggesting IBD, but doesn't account for her heart or kidney problems. House deduces that the IBD triggered ankylosing spondylitis, accounting for the heart and kidneys, and orders treatment. As House leaves, Taub gets a call from Rachel . He goes down to the parking garage to meet her, and she says that she can't do it. Taub admits that he's been an idiot and he doesn't need anyone else. They hug, assure each other that they love each other, and go home.
The next day, the team confirms that IBD treatment isn't working. They now have too many ideas. House notices that Taub doesn't have afterglow, and he explains that he chickened out because he couldn't hurt Rachel. They narrow it down to three possibilities and begin treating her. As they do, Thirteen suggests that Julia call Tom. However, all Julia can think about with Tom is that he's a liar. Thirteen finally tells Julia that he's been protecting her by not sleeping with anyone else. Julia thinks her marriage has been a sham, but Thirteen notes that Tom lied to keep her happy.
Sam comes to see Wilson at his office. They both apologize, but Sam admits that Wilson was right and she was selfish back then. Now she's trying to change, and she figures that Wilson has changed as well. Sam admits that she wishes they 'd had the fight ten years ago, and they both agree not to give House the credit.
None of the treatments work and Julia's kidneys continue to fail. Julia has allowed Tom to get back, and House notices that he brought lilacs. He remembers that lilacs attract bees, and HSP can rarely be caused by a bee sting. HSP also has a rash, but they didn't find a rash. House confirms that Julia was stung by a bee a month ago. House explains that she has Henoch-Schonlien Purpura, which causes lesions throughout the body and a rash on the skin. House checks her mouth and finds lesions inside, allowing them to successfully treat. Julia tells Tom that he loves her, but House notes that they've still got problems with Tom bankrupting them and Julia wanting to sleep with other men.
House comes home and finds Sam and Wilson happily playing poker together. He quietly puts the milk back in the door and leaves.
As Taub leaves for the night, he sees Maya going. He apologizes for canceling their date and she admits that she's sorry he did. They hesitate for a moment and then kiss. She asks if they he wants to go somewhere and he leaves with her.