A tragedia lirica in three acts that takes place during the reign of Queen Elizabeth I, when Robert Devereux, Earl of Essex, has been charged with treason. Sarah, Duchess of Nottingham, is in love with Devereux, and he loves her, but Elizabeth also loves Devereux, and the plot revolves around the jealousy and anxieties of these three and the Duke of Nottingham, Sarah's husband and Devereux's friend. A blue scarf that Sarah makes for Devereux and a ring given by the Queen to Devereux are the evidences that prove to Elizabeth and the Duke that something funny is going on.