A nursing home worker, Morgan, fakes an illness to get House to examine a cat which can predict the death of elderly patients. House doesn’t believe it… until Morgan becomes ill for real.

House and the team take on the case of Nick, a book editor who loses his inhibitions. The team realizes Nick has frontal lobe disinhibition, which causes him to speak his mind having no control over what he says and making him just like House. Meanwhile, House suspects Wilson and Taub are keeping something from him.

A patient with both male and female DNA has the team stumped. Meanwhile, House starts acting nicely, raising Cuddy’s and Wilson’s suspicions that something is terribly wrong.

House struggles with his own beliefs as he takes on a case of priest with a disturbing past who runs a shelter for homeless people and sees a vision of Jesus.

A former cancer researcher collapses in the middle of a cooking class, and the team is forced to reevaluate their own lives when they learn she gave up a promising career to seek personal happiness. Meanwhile, Thirteen suffers adverse reactions from the clinical trials, and Cuddy gives House a dose of his own medicine.

The team take on the case of a Special Education teacher who spits up blood and collapses in the middle of class. Meanwhile, Cameron finds herself taking on some of Cuddy’s duties, including dealing with House, and Foreman has to make a decision concerning Thirteen’s participation in the clinical trials.

House and his team deal with a man living in constant pain. Meanwhile, Thirteen receives treatment by Foreman while taking part in his clinical trial on Huntington’s Disease, and Cuddy tries to balance her hospital duties with her new baby.

House and his team deal with a bullied girl who collapses during her school’s Christmas program. Meanwhile, Foreman and Thirteen grow closer during the Huntington’s disease drug trials, House gives a patient a gift, the staff wonder who gave House a special gift, and Cuddy gets an unexpected gift.

The team takes on the case of a fitness guru on an all-natural diet who collapsed while filming a video. Meanwhile, Foreman conducts Huntington’s Disease drug trials and Thirteen signs on as a subject, Cuddy is forced to move into House’s office, and Kutner uses House’s name to run an online medical-advice website.

A man takes over Cuddy’s office and holds House, Thirteen, and several patients hostage. His demand? A diagnosis. The man forces Thirteen to act as a guinea pig for his treatments and House has to end the standoff before a SWAT team opens fire.