[5] Ray Abruzzo, Sasha Alexander, Eva Amurri, Curtis Armstrong, Annabelle Attanasio, Alexandra Barreto, Neill Barry, Angela Bettis, Jolene Blalock, Dennis Boutsikaris, Roger Aaron Brown, Sarah Wayne Callies, Samuel Carman, Willie C. Carpenter, Larry Cedar, Nick Chinlund, Shelly Cole, Bianca Collins, Joseph Culp, Vicki Davis, Alex Désert, Megan Dodds, Denise Dowse, Shane Edelman, Ethan Embry, Mark Damon Espinoza, Kim Estes, Nick Eversman, Rob Evors, Celia Finkelstein, Cali Fredrichs, Andrea Gabriel, Holly Gagnier, Adam Garcia, Troy Garity, Beau Garrett, Marcus Giamatti, Carl Gilliard, Ben Giroux, Jeremy Howard, JD Jackson, James Earl Jones, Orlando Jones, Sarah Jones, Paul Keeley, Doug Kruse, John Lacy, Katherine LaNasa, Andrew Harrison Leeds, Ana Lenchantin, Riki Lindhome, Eric Lutes, Tanner Maguire, Joshua Malina, David Marciano, James McCauley, Da'Vone McDonald, Doug McKean, Zoe McLellan, Jamie McShane, Gonzalo Menendez, David Monahan, Jonathan Murphy, Garikayi Mutambirwa, Trever O'Brien, Marnette Patterson, Artemis Pebdani, Jack Plotnick, Franka Potente, Esteban Powell, Laura Prepon, Anthony Tyler Quinn, Wes Ramsey, Kim Rhodes, Derek Richardson, Adam Rothenberg, Freda Foh Shen, Jon Seda, Noah Segan, China Shavers, Patrick St. Esprit, David Strathairn, Lee Tergesen, Desean Terry, Dale E. Turner, Bernardo Verdugo, Rick D. Wasserman, Charlie Weber and Jessica Whitaker.
House returns and has surprising news for Cuddy; on the advice of his therapist, Dr. Darryl Nolan, he's quitting his job; an ailing video game creator (Rick D. Wasserman) opts for treatments suggested by people on the Internet rather than listening to the team, which is now being run by Foreman.
The team treats a controversial African dictator named Dibala (James Earl Jones) who has fallen ill while coming to America to give a speech at the United Nations.
Final diagnosis: Blastomycosis (Dibala) and Phantom limb (Murphy) A wealthy businessman (Lee Tergesen) brings his son (Tanner Maguire), who is suffering from inexplicable stomach pains, to Princeton Plainsboro and insists on having Dr. House handle the case.
Final diagnosis: Primary Antiphospholipid syndrome Cameron pushes the team to treat a man (Jon Seda) whose father, grandfather and great-grandfather have all died of a sudden heart attack before the age of 40, but House is reluctant to take the case without distinctive symptoms.
Final diagnosis: Intracranial berry aneurysm of the brain stem After a wild night out, a teenage girl (Annabelle Attanasio) is brought to Princeton Plainsboro with severely swollen appendages.
Final diagnosis: Vibrio vulnificus and haemochromatosis After House's medical license is reinstated, he reclaims his role as Head of Diagnostics in time to treat Hank Hardwick (Troy Garity), an adult film star admitted to Princeton-Plainsboro for pulsating eye pain.
On the eve of Thanksgiving, House and the team take on the case of James Sidas (Esteban Powell), an exceptionally brilliant physicist and author who traded his successful career for a job as a courier.
Final diagnosis: Thrombotic thrombocytopenic purpura complicated by dextromethorphan abuse and multiple accessory spleens An old friend and former patient (Joshua Malina) of Wilson's experiences paralysis in his left arm during a hunting trip.
Final diagnosis: Hughes–Stovin syndrome The team takes on the case of Valerie (Beau Garrett), an attractive executive experiencing random episodes of excruciating pain.
Final diagnosis: Psychopathy secondary to Wilson's disease House and the team rush to treat an ailing college American football star (Da'Vone McDonald) in time for the patient to compete in NFL tryouts.
Final diagnosis: Paraneoplastic syndrome secondary to melanoma During a day in the life of Princeton-Plainsboro's Dean of Medicine, Dr. Lisa Cuddy, the inner workings of the hospital are seen through her eyes.
Final diagnosis: Whipple's disease House and team tries to diagnose a high school senior (Cali Fredrichs) suffering from blackouts and hallucinations, and are forced to take a controversial approach.
Final diagnosis: Anabolic steroid abuse accelerated by hemlock poison A woman in an open marriage (Sarah Wayne Callies) suddenly becomes ill during a date with her boyfriend; House tests Wilson and Sam's relationship.
Meanwhile, House spends extracurricular time with his Princeton Plainsboro colleagues, performing a karaoke rendition of a Gladys Knight & the Pips classic with Foreman and Chase.