Martha Meredith Masters, M.D, Ph.D. . was a major character on House during the seventh season of the series, with a special appearance at the end of the series. She was a third year medical student who graduated medical school in Last Temptation and became a medical intern. Masters filled in for Thirteen for a time while Thirteen was on leave from the hospital. Masters quickly became a fan favorite and a darling of the critics, creating a character who was a true match for House’s intellect and abusive behavior. She also provided him with two challenges. Unlike his other team members, who were all board certified before they reached him, House has to deal with someone bright but untrained. He was also challenged by Masters unfailing honesty and belief in the better nature of people.