Lady Agatha Wingate is the headstrong daughter of a peer of the realm, Lord Arthur Wingate. She has always admired a family friend Uncle Alfie. When she was a little girl, he had such marvelous stories to tell. As Agatha grew into womanhood she began to recognize his stories. Uncle Alfie was, in fact, Sir Alfred Stately. He was the minister of a government agency; "The Bureau of Domestic and Foreign Affairs". Agatha was delighted when she figured out that Uncle Alfie was a spy.
When Victoria became Queen of the United Kingdom, Lord Melbourne thought that when introducing the Minister of Domestic and Foreign Affairs, having a woman spy might be a positive diplomatic gesture.
Neither Lord Melbourne nor Sir Alfred Stately realized that Lady Agatha Wingate would take her role very seriously.