S4, E2: House has relented in regard to interviewing potential team members, but he’s doing it his own way. He has called in all 40 applicants for the open spots on his team (including guest stars Olivia Wilde, Kal Penn, Peter Jacobson, Anne Dudek and Edi Gathegi), each numbered individually by runners’ bibs, and puts them to the test in a Darwinian trial period. As he drills the fellows and arbitrarily fires some along the way, he is approached by a fighter pilot named Greta, a candidate for NASA’s astronaut training program. Greta suffers from a neurological disorder in which she is converting visual images to sound, or hearing with her eyes. Knowing that NASA would reject any possibility of her becoming an astronaut if they knew of her problem, Greta begs House to treat her in secret. Keeping her identity private, House takes the case to his fellowship candidates and pits them against one another to come up with an accurate diagnosis. Meanwhile, House is ruffled when he thinks he sees Cameron, Chase and Foreman in the hospital hallways.