In All in a Garden Green, thirteen-year-old Erica Pickins walks through a door of the old manor house, Hengrave Hall, on a family visit to England and finds herself mistaken for the elder daughter of the house, Margaret, in the year 1578. Queen Elizabeth herself is about to arrive on a royal visit, and, because of her musical talent, Erica becomes the most important part of the desperate attempts by the Catholic family to entertain the Protestant Queen.