The American Gilded Age was a period of immense economic and social change, when empires were built, but no victory came without sacrifice. Following the Opera War, the old guard is weakened and the Russells stand poised to take their place at the head of society. Bertha sets her sights on a prize that would elevate the family to unimaginable heights while George risks everything on a gambit that could revolutionize the railroad industry — if it doesn't ruin him first. Across the street, the Brook household is thrown into chaos as Agnes refuses to accept Ada's new position as lady of the house. Peggy meets a handsome doctor from Newport whose family is less than enthusiastic about her career. As all of New York hastens toward the future, their ambition may come at the cost of what they truly hold dear.