At a restaurant cooking class, the chef's assistant Dana Miller begins to feel sick. As she falls to the floor, she describes her list of symptoms. Dana is actually a doctor.
Thirteen and Foreman wake up in bed together, happy. Meanwhile, looks at a mug he has kept since Amber left it on the kitchen countertop.
House arrives at the hospital to find the elevators are out of order. He drags himself up the stairs, and is in pain when he gets to his office. The team is waiting with Dana Miller's case. The patient is a renowned cancer researcher looking for a cure for retinoblastoma. Dana has suffered spontaneous pneumothorax. House orders steroids for asthma and a chest CT to look for hyperinflation.
As Thirteen and Taub tend to Dana, she explains that she left medicine for cooking because she had a uterine myoma and needed emergency surgery. This caused her to reevaluate what makes her happy.
Cuddy acknowledges to House that she blames him for Cameron choosing not to replace her. Cuddy wants to punishing him for making her leave her baby and come to work. House rips the sign off the broken elevator and enters it.
Examining the CT images, the team sees that Dana does not suffer from asthma but she has increased interstisal markings that look like pulmonary fibrosis. They debate the virtue of Dana leaving medicine, when she was close to a cure for retinoblastoma. House calls for a biopsy but stops Foreman before he leaves to discuss Thirteen's condition. Foreman then runs a mental acurity test on Thirteen with images on flash cards. She says she has a headache, which worries Foreman.
Taub is about to take the open lung biopsy when he notices that Dana's abdomen is swollen. He sticks a syringe in it because it is filled with blood. Later, as the team walks the hall, Kutner reports an ultrasound pinpointed Dana's hepatic artery as the source of bleeding. House stumbles when he enters his office because someone put a tripwire at the door. House knows who did it.
Taub displays an MRI of the patient's liver. It is clean. Foreman finds what could be a granuloma on the MRI. House keeps him in the office to ask about Thirteen. Based on the MRI, House thinks she has lost her peripheral vision.
House is tending to his wound in an exam room when Wilson enters. House plans to lay low with Cuddy. Wilson sees Dana Miller's patient file and goes to see her. She remembers meeting him at a conference. He questions why she quit when he needs her research to battle cancer with the children he treats. Dana asks if he is angry because he is stuck in a rut and unable to move forward.
Taub suggests to his wife that they have a child. She reminds him that he knows she does not want to be a mother.
Thirteen is working in the lab on Dana's biopsy when Foreman comes in to test her eyesight. It is failing. She knows she is on the trial's test drug. Foreman confesses that he switched her from the placebo. Thirteen digests this and gets freaked out that he would risk so much for her. She gets an MRI. Foreman is in the control room, and he reacts to the image on the monitor.
Foreman brings Dana her negative test results and notices a bloody scrape at her hairline. Upon closer inspection, he sees that she scratched the area through to her brain. She is rushed to surgery, and Taub announces to the team afterwards that the scratching did not cause any brain damage. House orders a brain MRI. He turns to grab his cane but it is gone. He spots a janitor's mop and bucket and takes that as a stand-in.
House enters Cuddy's office, leaning on the mop and bucket. He has a phony article about working mothers.
When Dana's brain MRI comes back negative, House suggests polyneuropothy. Foreman grabs his coat and House follows him down the hall. Foreman tells him that Thirteen has a tumor in her optic chiasm and he is headed to confront the drug company. House talks him down, advising that it is in Thirteen's best interest for Foreman to keep his medical license.
As Taub attaches electrodes to Dana's head, she feels a strong shock. Yet Taub had not even given her one yet. Dana suggests Lhermitte's sign.
Foreman goes to Thirteen's apartment where she has a bleeding leg from a fall. She has gone blind.
House tries to sleep on Wilson's sofa because Cuddy had called the utility companies as "Mrs. House" to turn off his electricity. Kutner and Taub had been paging him all night about Dana's Lhermitte's sign. Taub suggests the diagnosis of an aggressive spinal hemangioma.
House goes to Thirteen's apartment to find Foreman. She is sitting there alone and tells House that Foreman went to the drug company. House has her call Foreman to force him to turn back.
Wilson chastises Cuddy about physically hurting House. Meanwhile, House and Foreman administer radiation therapy to Thirteen.
Taub and Kutner perform the MRI on Dana and find the hemangioma and an additional mass. There are also masses in her spine, lungs and pericardium. They show House the MRI slides which uncovers mesothelioma that was not there earlier in the treatment. House says to get Wilson to do a confirmation biopsy. Kutner wants to know what is going on with Thirteen and Foreman.
Wilson takes the biopsy from Dana and apologizes for judging her. She was right about him being stuck. He performs the biopsy, and she starts bleeding. Wilson informs House and Taub about the biopsy. They discuss diseases that cause masses to bleed. Taub's pager rings because Dana's heart has just stopped. She has cardiac tamponade, which is bleeding that is smothering her heart. Kutner tries to remove the blood from the chest, but it appears in other orifices. Taub and Kutner explain to House that they are trying to keep Dana from bleeding to death. House instructs them to cut off the arteries feeding the blood to the tumors.
House finds Cuddy waiting for him with his cane. She apologizes for her inappropriate behavior, which House jokingly blames on her menstrual cycle. Suddenly, House makes a connection and rushes to where Taub and Kutner are prepping Dana for the arterial embolization. He goes through the contents of the garbage can to find an empty box of sanitary napkins. Dana is menstruating and is bleeding everywhere. House diagnoses ectopic endometriosis. When she had a myoma, the surgeons cut through her uterine wall, sending endometrial cells into the bloodstream. They grew all throughout her body, and bled when her uterus bled. House tells them to cut out the masses.
Thirteen is resting in a patient room and embraces Foreman.
Taub visits Dana, who is recovering from the surgery to remove the endometrial tissue. She tells him that he should go to bed happy tonight.
Foreman watches several patients receiving the trial drug. He takes out his phone and makes a call. Later, Foreman tells House that he came clean to the trial administrators. He can retain his license if he keeps away from all clinic trials.
Taub and his wife discuss having a child. Thirteen and Foreman wake up together. And Wilson takes Amber's mug from the counter and finally washes it.