S4, E11: When Dr. Cate Milton (guest star Mira Sorvino), a psychiatrist trapped at the South Pole and the research station's only doctor, becomes ill in the middle of her assignment, she and Dr. House are thrust into a long-distance relationship of sorts. Unable to get Cate out or any additional medical supplies to the South Pole station, House and his team must resort to treating her via webcam. House and his team walk the doctor through a series of makeshift and painful diagnostic tests she must perform on herself. Cate pushes back at House's every recommendation, and is unwilling to risk valuable station medical supplies until he can provide valid proof for his diagnoses each step of the way. While House and his team helplessly watch her condition worsen, House's usually icy demeanor surprisingly softens as he searches for ways to save her life. Meanwhile, House does some detective work of his own and is surprised to learn who Wilson has been dating.