The title, The Moonstone, refers to a brilliantly beautiful but flawed gem seized by a British officer in India. The officer brings it back to England as a family heirloom with a supposed curse placed upon it. The officer leaves the stone to his niece, Rachel Verinder, for her to inherit when she turns 18.

This classic work by Wilkie Collins is an early example of the modern detective novel that set many of the ground rules of the genre.