A young boy, Lue, is asleep in bed when an ugly hag woman comes into his room. She grabs Lue and starts choking him, and the boy yells for his mother Lida. However, when she comes in, there's no one there. Lida assures him that he's just having a bad dream, but Lue is unable to get a breath and finally passes out.
House arrives at the hospital and Foreman complains that he's been trying to call him for two hours. He describes Lue's case but House is more interested in his dreams about Dominika. However, when Foreman tells him that Lue has dreams about a hag trying to strangle him, House perks up. He brings a bunch of cases to the team of Hmong who died in their sleep of respiration problems. Chase points out that Lue is dreaming about a demon, while Park insists that dreams don't matter. House notes that she's defensive about dreams and wonders what she's dreaming about, and then tells Park and Chase to give antibiotics while Taub and Adams check the home for toxins. Park asks to go with Taub, saying it was her idea, but House figures that she's uncomfortable around Chase because she's having sexual dreams about him.
As Adams treats Lue, Chase asks Lida if someone might have taught Lue about evil spirits. She says that she's an engineer and doesn't believe in evil spirits, and then goes to her son.
House goes to see Wilson, who is checking a woman for breast cancer. Wilson gets him out and has to listen as House describes his metaphorical sex dreams about Dominika. However, Wilson has no interest in hearing about it.
As Park and Taub check the house, he says that it would be weird if she didn't have dreams about Chase. He admits that he's had dreams about having sex with his co-workers and it doesn't bother him, and Park worries that it might means something. Taub figures that Chase just represents work and she's in love with her work. Before they can pursue the matter, they smell something moldy and go upstairs to investigate. They find Lue's bedroom with a pattern drawn on the floor in the blood of a dead pig.
Park and Taub confront Lida, who says that she has no idea how a dead pig got into her room. However, she soon realizes that her father Xang is responsible. When she confronts him, he insists that he did what Lida should have done weeks ago. Lue goes into cardiac arrest and they manage to reestablish heart rhythm. The team gets back together and explains that Xang performed a Hmong ceremony that is supposed to call Lue's soul back. Xang believes that Lue had his soul stolen because Lue's father beat a man to death and went to prison. Adams suggests PSTD but Park explains that Lue never knew what happened to his father. House tells them to echo the pericardium and check for toxins in the home samples. As they go, Park says that she enjoys her job very much.
House goes to Wilson's office and starts talking about his sex dream about Dominika. Wilson figures that it's guilt because House threw away her INS letter and is keeping her prisoner, and tells House to tell her the truth.
As Park and Chase run tests for toxins, she acts nervous around him and he suggests that it's normal he might pop into her subconscious. She asks if he's ever had sex with him and Chase pauses before saying no, and Park figures that he's trying not to offend her. Taub and Adams confirm that the echo was negative but Lue has abdominal pain and constipation. Chase suggests that they biopsy his thyroid and the others agree, and Park congratulates him on his call.
That night, House has Dominika in for takeout in his office and admits that she knows him pretty well. She figures that he has news from the INS, but House lies and says that it could be another month until they finalize their decision. Dominika says that it's been fun staying with him but she wants it to be legal, and House assures her that it will. Meanwhile, House suggests that they shoot someone.
Adams tries to give Lue a local to do the biopsy, but he insists that he doesn't want it. The boy starts speaking in Hmong and only Xang understands what he's saying. The old man insists that it's the demon speaking because Lue doesn't speak Hmong. Lue starts to seize up and the doctors manage to stabilize him. Back in differential, Taub wonders how Lue could have spoken a language he doesn't know, and House says that they had no way of knowing what he said. When Adams points out that Xang translated, House figures that the grandfather heard what he wanted to hear and Lue was just speaking gibberish. Chase figures it's a neurological symptom and Park agrees. House wonders why they're agreeing and figures they shouldn't be able to even look at each other. Adams suggests encephalitis and House orders a MRI to confirm.
Chase talks to Lida about their diagnosis, but Xang insists that they're wrong. He explains that his son Kao was having the same dreams that Lue is having now and they drove him to murder. Chase tells him not to scare the boy, insisting it won't help him get better/.
Taub and Park run the MRI and she says that she had a dream about Taub. He seems interested and Park notes that's the normal reaction when a woman says that she has a dream about a man. Taub wishes them the best of luck even though he notes that they're completely different, and tells her not to let House screw it up.
House takes Dominika to the firing range and she easily outshoots him. She explains that she served one year with a police unit and never told House. He gets a text confirming that the MRI was negative and Dominika wonders why he can't believe in demons. When she starts talking about physics and admits that she read one of House's books, he's impressed.
Xang talks to Lue and tells him that the doctors aren't looking in the right place, and warns his grandson that he's angered his ancestors. He has Lue pray to their ancestors for forgiveness and then says that they have to do more by stopping the air that the demons occupy. Xang then starts choking the boy, insisting that it will help him. When Taub and Lida come in, they discover that he's having another dream. Lue wakes up and says that Xang was choking him, and Taub finds bruises on the boy's neck.
Back in differential, Taub describes what happened and begins to wonder if dreams can cause physical manifestations. House is still interested in Park's dreams and figures Chase isn't teasing her because he likes the attention. House suggests liver failure due to fibrosis to account for all the symptoms and orders a biopsy. As Adams and Taub perform the biopsy, Lida admits that she doesn't want to believe that dreams can cause Lue's problems. Taub admits that he's having trouble accepting the idea and Lida notes that so far they haven't been able to account for the symptoms again.
Park comes to Chase with the test results and hesitates to meet his eyes, and he tells her that he wants Park to treat him as a friend. She snaps at him and he snaps back, and then they kiss and she throws him down on the couch... and Chase wakes up from his sex dream. Park is there and tells him that the liver biopsy is back, and he says he'll be right there.
Adams and Taub tell Lida that the test for fibrosis was negative. A nurse calls them into Lue's room and they watch as he apparently levitates into the air. They report the incident to House but he insists that there's a rational explanation. House notes that Chase isn't addressing anyone in the room and then demonstrates an impromptu levitation. He figures that Xang was handling the illusion and Lue was a distraction, and notes that Chase is avoiding Park today but not the day before. Chase suggests hypocalcemia and House agrees, orders beta-blockers, and deduces that Chase had a sex dream about Park.
Taub and Chase prepare treatment but Lida notes that they haven't been successful so far. Xang believes that the calling ceremony in the house didn't work because Lue was elsewhere, and she decides to check Lue out and take him home for the exorcism. Lida says that Xang might be right about Kao committing murder while he was possessed, and insists that her son needs his soul back.
House takes Lida's decision to Foreman and he agrees with her, saying it's no worse than having a priest tending to a patient. When House threatens to quit, Foreman figures that he's not going anywhere. However, House says that it may involve animal sacrifice and Foreman agrees to talk to Lida. She says that she wants to do everything she can and threatens to take Lue, but Foreman refuses to release him as long as he's sick. Lida says that she talked to a lawyer and confirmed that they can't say no to her religion. Foreman hesitates and then asks for 24 hours.
House comes home and hears Dominika complaining on the phone. She tells him that a letter came in the mail and House apologizes. However, before he can explain further, Dominika says that the letter is from her uncle saying that her aunt has been institutionalized. Upset, she hugs House and asks if he's going out, and House says that he can stay.
Adams checks on Lue and discovers that he's non-responsive. As they try to revive him, Lida realizes that they're wrong again and calls Xang. The grandfather performs the Hmong ceremony in the hospital room while the team meets for differential. House isn't interested since Lida has given up, and figures that if they do cure Lue then Xang will take the credit. He figures that Lue is better off dead if Lida embraces faith over science. House suggests PDA even though he's not an infant and hasn't demonstrated any symptoms. He figures the antibiotics may have set it off and Adams notes that the treatment for an infected ductus is ibuprofen. House refuses to let them treat and Chase points out that he's letting a patient die to prove his point. In response, House says that he'll respect their diagnosis but refuses to let them treat with ibuprofen and confirm his diagnosis.
Taub and Adams go to see Lida as Xang continues his ceremony. Lue crashes and Adams decides to give him the ibuprofen despite House's orders.
Later, House is at home drinking and Dominika asks why he's sulking. He says that he isn't but Dominika knows better, and House explains that either religion is killing Lue or he is. Dominika crawls on top of him to comfort him and then kisses him. She starts to undress but House's phone rings and she picks it up before he can stop her. It's from the INS informing him that Dominika has become an American citizen. However, they tell her that they already sent her several notices. House apologizes but Dominika walks out of the room without a word.
A nurse informs Taub and Adams that Lue's condition is improving. They check and confirm that he'll be okay. Lida assumes that her grandfather's ceremony was successful, buy Adams explains that the ibuprofen is what cured him. The mother doesn't believe her and tells Lue that his grandfather saved him.
Dominika packs, hugs House, and leaves.
As Chase waits for the elevator, Park comes up and asks if she was good. He insists that it didn't mean anything and the idea was inevitable, but she tells him that it means something. Park thinks that it could mean the obvious, or it could just mean that they trust each other. Chase admits that it's possible and she farts to test her theory.
House comes to see Wilson and notes that Adams defied him and Dominika moved out. As he bemoans his fate, Wilson says that he has stage II thymoma cancer and just got it confirmed that morning. For once, House has nothing to say.