Keys is the eleventh book in the Lady Grace Mysteries, a series written in the form of the diary of Lady Grace Cavendish, a teenager girl who is goddaughter and Maid of Honor to Queen Elizabeth I. Grace solves mysteries at court with the help of her friends Masou, who is one of the Queen`s fools, and Ellie, who is her best friend despite the fact she is Grace's servant.

Queen Elizabeth I and her court have just arrived at her palace of Hampton Court. Grace and Ellie are out walking the Queen's dogs when they stumble upon a terrible sight - a man who has just been murdered. The man is Nicholas Urseau, the royal clockmaker. From the start, most people at court believe the murderer to be Mr. Urseau's apprentice, Charles Doute, because he was found next to the body. But Grace has her doubts. Charles seems heartbroken at his master's death, and she fears an innocent man may be punished or even killed for a murder he didn't commit. She decides that if no one will believe her about Charles Doute's innocence, she must solve the mystery herself. Enlisting the help of her friends, she sets out to solve yet another puzzling mystery at court.

Keys was another enjoyable read in the Lady Grace mysteries series. Although it would be most enjoyed by readers who have read earlier books in the series, the plot in this book can stand on its own. I recommend this book, and others in the series, to young readers who enjoy historical fiction, as well as to older readers with a special interest in reading about this time period. ( )