In the pilot episode, John Carter is introduced as a third-year medical student on his ER rotation. He is assigned to Benton, who proceeds to give Carter a hard time. They seldom get along and their personalities clash on many occasions. Benton is more ambitious and focused on surgery whereas Carter is more compassionate and willing to spend time with patients, a trait that "drove crazy" as he put it to Cleo, although he considered Carter to be a talented and smart doctor. In Season 3, Benton develops appendicitis and Carter operates on him. However, Carter eventually decided to leave surgery for emergency medicine, a decision that caused him to clash with Benton. Nonetheless, the two have reconciled and, despite the fact that they have interacted less since Carter's transition to emergency medicine, formed a deep friendship.