Hugh Laurie stars as acerbic but brilliant New Jersey medic Dr Gregory House in the fourth series of the Emmy- and Golden Globe-winning medical drama. This week, House must diagnose symptoms affecting a psychiatrist on a research base at the South Pole. Communicating via webcam, House’s patient has only limited medicine and equipment with which to treat herself.

House must diagnose a case at a distance this week when a scientist at a research base in Antarctica is taken ill. Dr Cate Milton (Academy Award-winner Mira Sorvino) complains of vomiting and a sharp pain in her side. High winds mean that evacuation is impossible and the base is equipped with only limited medical supplies and instruments – making accurate testing all but impossible.

House’s initial diagnosis is kidney stones and, communicating by webcam, he orders Cate to run a basic set of tests with the equipment at her disposal. The results show that Cate’s kidney function is declining, but she frustrates House by refusing to take antibiotics as a precaution against infection. “We have a limited supply of medicine and I’m not about to waste it,” she says.

Cate’s symptoms worsen when her right lung begins to collapse. With House and Foreman instructing her via the camera, Cate stabs a syringe into her chest and re-inflates the lung. Her condition stabilises immediately, but House’s kidney stone theory is left in tatters.

A set of x-rays then gives House cause to believe Cate may have cancer, but with no operating room on the base and no lab to test for tumours, it is impossible to conduct a normal biopsy. Cate performs a physical exam on her body and finds an enlarged node in her belly, from which she withdraws a sample of fluid with a needle.

Tests prove the node is non-cancerous, but the good news is short-lived, as Cate develops further pain in her side. It would seem that both her kidneys are failing – suggesting she has an autoimmune disease. House tells her she needs to take a drug called prednisone, but Cate refuses because another scientist on the base may need it for his asthma. She accuses House of leaping from one theory to another without substantiating his claims. “Show me the proof that it’s autoimmune, and I’ll take the prednisone,” she says.

Unfortunately, there is no easy way to test House’s theory. Foreman hits on the radical idea of sending Cate out into the cold, arguing that exposure to freezing temperatures has been known to reduce autoimmune symptoms – but House surprises him by rejecting the proposal out of hand. “This is a good idea,” Foreman says. “It’s perfect for you – experimental, risky.” So why is House against it?

Foreman and Wilson realise that House has developed a bond with his feisty patient – and it may be affecting his judgment. Just when it seems that Cate may have to try Foreman’s dangerous test after all, she collapses and slips into a coma. The only person who can help her now is Sean, the station mechanic. With the autoimmune theory disproven, House needs to find out whether the cause of her coma lies in her kidneys or in her brain. To this end, he asks Sean to drink Cate’s urine – in the hope that its taste will establish whether her kidneys are to blame.

Without hesitating, Sean performs the task and reports that the urine has a watery taste – suggesting the cause of the coma is in her brain. Sean’s unquestioning action has taught House another salient fact – that the mechanic is in love with Cate. “Now I know that, I can get you to do anything to save her,” he says. House immediately puts this belief to the test when he tells Sean, “You’re gonna drill a hole in her skull.” The procedure is the only way to relieve the pressure building in Cate’s head, but can Sean hold his nerve? And can House put his own feelings for Cate to the back of his mind?