The Duke's two sons also prove burdensome. Lord Silverbridge follows the wishes of his father by entering Parliament. He had proposed to Lady Mabel Grex, whom he has known all his life. She turned him down, although with an indication of a more welcoming answer another time. However, Lord Silverbridge becomes enamoured with American heiress Isabel Boncassen. She agrees to marry him, but only if the Duke is willing to welcome her into the family. At first, the Duke disapproves; and he disapproves even more of his daughter's suitor. To add to his troubles, Gerald, the younger son, gets himself expelled from Cambridge after attending the Derby without permission.
However, by the end of the book, the Duke grows closer to all three of his children; he allows the engagements of both son and daughter, and he is invited once more to take a part in the government.