Things are different in America. He's surrounded by people speaking his native tongue with a peculiar accent---and they all think he's the one who's talking funny. The climate isn't what he's used to, either, but one truth is universal: the patients still hemorrhage, code and die the same as Down Under.
Here, he's Dr. Chase---he's used to being addressed by his surname from his school years, but it's no longer followed by 'Oh-you're-Rowan's-son-aren't-you?'---and once he realizes that, proving himself becomes much easier. Tucker, another of House's fellows, says their mentor is a bastard, but Tucker---who's eight years older than he is---is a load of figjam. He's been coasting on modest brains and charm, and House doesn't give a rat's ass about charm. Tucker and DiBiase whinge about House's abrasive manner, but Chase has no problem with it. Whatever else you may think of the senior doctor, he's dead honest, and to Chase's way of thinking, that's a good thing. He may insult and criticize and badger them all, but you always know what's on his mind. He's not going to keep things inside, and then one day surprise you with a curt, "Enough is enough. Get packed."
When DiBiase quits and House brings in an immunologist named Cameron, Chase gets to her before Tucker can clue her in on her new boss. "He's a tough bastard, but you'll learn a lot. He'll try to make you doubt yourself. As long as you know what you're talking about, you'll be okay. Don't try to bluff him. It won't work. Don't get in his face, but don't back down. You've got the right stuff, or he wouldn't have hired you."
When he's the senior fellow, it's him and Cameron and a guy named Foreman---a neurologist, good guy, good doctor---although Foreman pushes back when House gets in his face. Sometimes that annoys the hell out of Chase. He learned long ago that being low-key and smart gets better results than being confrontational, but House screws with all of them equally. He picks on Cameron because she's pretty and tender-hearted, Foreman because he's black and used to be a delinquent, and himself for being Aussie and, according to his boss, a suck-up. House is entitled to his opinion, so Chase shrugs off the implied slur.
His private life isn't much better than it was when he was in school; he hasn't found anyone to be with on a long-term basis. He's has a couple brief affairs, but in the long run, it's easier to just do his job and go home and not get into relationships that are sure to end messily. Being a workaholic isn't hard when you love your job, and Chase does. Medicine has taken the place of God in his life. He's dedicated himself to it; sometimes this vocation also leaves him bitterly disappointed, but he still needs it, needs its mysteries to ponder and its continual testing of who he is.
His dad comes over for a conference, and House gets him to consult on their current case, a young boy whose symptoms are baffling. Being "Rowan Chase's son" again stirs up a lot of old trash, but in the end, it dawns on him: this is his dad, reaching out to him for a change. They've been debating diagnoses for days, but his dad hasn't stepped over the line between their personal business and their mutual profession. And now that he's where he is in his own life, Robert Chase can admit that it would be easy to neglect a family in pursuit of his calling. He can't blame his dad for that any more.
He catches Rowan on his way to the airport, and although they don't have much time, the ice between them is finally broken. The next time he visits, Doctor Robert Chase promises himself, they'll melt the rest of it.