House enters a mental health facility after he becomes unable to tell fantasy from reality.





House and the team are given the challenging case of a ballerina (Jamie Tisdale) whose lungs collapse during a performance. After first facing the prospect of never dancing again, the ballerina’s future seems even more grim when the treatment causes her skin to fall off. House must solve this daunting puzzle while going to desperate measures to cure his perceived insomnia.





The case of a deaf 14 year old boy, Seth (Ryan Lane), who collapses in the middle of a wrestling match after ‘hearing’ explosions is brought to Princeton-Plainsboro, and the team faces an ethical dilemma when Seth’s mother (Clare Carey) decides to forego cochlear implants. House suffers from lack of sleep, which starts to play tricks on his mind, but he finds it is more of a help than a hindrance.





Staff at Princeton-Plainsboro, particularly House and the team, try to deal with the recent tragedy while Cameron presents House with the case of an environmentalist who collapsed in the middle of a protest.





An older woman, Charlotte, who has been taking care of her husband Eddie (guest star Meat Loaf) for the last six months, is rushed to Princeton-Plainsboro for treatment after collapsing at Eddie’s deathbed from respiratory failure. The husband and wife become a double mystery for House and the team as Eddie’s condition improves while Charlotte’s deteriorates. With both of their lives nearing an end, the team is forced to make a difficult choice when Charlotte informs them that she wants Eddie to have her heart should she die before him. Kutner is found dead after an apparent self-inflicted gunshot wound to the head. It seems to indicate suicide; however, House thinks it was murder. He struggles to solve the mystery, thinking he is losing his insight by not being able to notice Kutner’s behavior leading up to the tragedy.





House is injured in a motorcycle accident in New York and finds himself in bed next to a patient (Mos Def) suffering from complete paralysis from a bicycling accident. As House transfers the patient to Princeton to determine what’s wrong with him, Wilson tries to find out why House was in New York in the first place.





Nursing-home worker Morgan (guest star Judy Greer) fakes sick to get House’s attention after the home’s pet cat sleeps next to her. It seems that the cat only pays a visit to people if they are about to die and does so with alarming accuracy. While House dismisses Morgan as a nut job, he is intrigued by her theory on the kiss-of-death cat, and sets out to disprove it. When Morgan falls seriously ill, he and the team are forced to get to the bottom of both mysteries. Meanwhile, Taub struggles with his finances and reconnects with an old high school friend at the clinic whose business successes present Taub with an entrepreneurial opportunity he had not previously considered.





House and the team take on the case of Nick (Jay Karnes), a book editor who loses his inhibitions and starts insulting coworkers at a dinner party one night before falling ill. The team realizes Nick has frontal lobe disinhibition, which has caused him to lose his filter and vocalize all of his innermost thoughts, resulting in extremely insulting outbursts. As Nick’s free speech leads to some amusing and insightful comments regarding the team, he must deal with the consequences of being unable to lie to his wife and everyone else important in his life. Meanwhile, House suspects Wilson and Taub are keeping something from him when he catches them both in a lie.





The team encounters a teenage boy who collapsed from severe pelvic pain after playing basketball. The boy was born with a condition called genetic mosaicism, or both male and female DNA, and the boy’s parents inform House and the team that the boy is unaware of his condition. They chose a gender for him when he was born and raised him accordingly. However, when his condition worsens and his life is threatened, the parents wonder whether they made the right decision. Meanwhile, Cuddy and Wilson suspect something is wrong with House when he starts acting way too nice.





When a priest who runs a homeless shelter sees a bleeding Jesus hovering at his doorstep, he is admitted to the ER. House takes on the case as a distraction for the team while he confronts Foreman and Thirteen about their relationship. The team soon learns the priest had been involved in a molestation scandal that caused him to lose his faith. However, just as they are about to dismiss his case, the patient’s condition takes a drastic turn for the worse, and House grapples with his past and his belief in the “Unfaithful”.