A man who has always relied on two things to get by: his limitless fortune and the good sense of lifelong nanny Hobson (Mirren) to keep him out of trouble. Now he faces his biggest challenge choosing between an arranged marriage that will ensure his lavish lifestyle or an uncertain future with the one thing money can't buy - Naomi (Gerwig) the only woman he has ever loved. With Naomi's inspiration and some unconventional help from Hobson Arthur will take the most expensive risk of his life and finally learn what it means to become a man.