3x21 "Family" House treats Matty, a boy with upper respiratory symptoms as he prepares to donate his bone marrow to his brother Nick, Wilson’s leukemia patient. The team needs to isolate the infection, working against the clock while Nick awaits the transplant in a clean room.
3x22 "Resignation" House and the team treat Addie, a college student who is coughing blood. A series of infections leads House to believe that she suffers from Complement H deficiency, a fatal genetic condition. Her apathetic reaction upon receiving this dire news leads him to reconsider.
3x23 "The Jerk" House treats Nate, a 16-year old chess prodigy who beats (literally) an opponent to a pulp after winning a match. In addition to unexplained rage attacks, Nate suffers severe headaches. The kid has been an obnoxious brat for years, and now with these symptoms, House wonders if there’s a physical reason behind the bad attitude.
3x24 "Human Error" A Cuban couple, Esteban and Marina, risk their lives to travel in a small boat from Havana to New Jersey to see the famous House. He diagnoses Marina, trying to distinguish symptoms caused by the trip from symptoms caused by her illness.