We meet Martha M. Masters on this episode. She's a genius third year medical student that Cuddy insists joins House's team.
As you might expect, the doctor objects to this addition and tests Masters often. She's a bit shy during differentials, but the main problem is that she has a moral code she refuses to ignore. She always tells patients the truth, a fact that irks House and endangers these patients in his view. He fires her about 12 times during the episode.
But Masters ends up coming through, helping to solve the case of a political consultant on the verge of death. House hires her for real at the end of the episode, but he also makes a major mistake with Cuddy:
In order to get her approval for a treatment, he fabricated a positive test for Hepatitis C. Cuddy learns this at the conclusion of the hour and is clearly unhappy with her boyfriend.