It is a fantasy novel and is set in Victorian times. There is a peace between humans and Faerie that hinges on a special ring. An upper-class young girl who has come upon bad times and is making a living as a pickpocket manages to steal the ring but when she finds out its significance she has to return it to the palace under the noses of the royal princes. The ring disappears and a war could ensue. I don’t want to spoil the end, so read the book – it is worth it and you will want to read the sequel.