"The Moonstone" by Wilkie Collins is a groundbreaking epistolary novel, often hailed as the first full-length detective story in English literature. This captivating tale revolves around the mysterious theft of a priceless diamond, the Moonstone, and the ensuing investigation that unveils secrets and motives among a diverse cast of characters. Collins not only sets the stage for modern detective fiction but also showcases progressive social attitudes, particularly in his portrayal of servants. Ideal for readers aged 12 and up, this classic work combines suspense, intrigue, and social commentary, making it a must-read for both young adults and seasoned literature enthusiasts.