The Moonstone is a novel published in 1868 by Wilkie Collins. It is often described as the first detective novel and was one of the more important works in the formation of the genre. Like other detective novels, it is primarily a plot-rather than character-driven novel, engaging the reader with mystery and suspense rather than complex psychological portraiture.

Franklin Blake

Franklin Blake is the protagonist of the novel and a model for the "amateur" detective that is a staple of the genre. He falls in love with and eventually marries Rachel Verinder. He is instrumental in solving the mystery of the missing Moonstone. He initially transports the gem to Rachel, is nearly killed by the vengeful Hindus seeking to recover the stone, ends up getting drugged and being suspected of theft, but eventually is seen clearing his name and marrying happily.

Rachel Verinder

Rachel Verinder is the niece and heir of the evil John Herncastle. Herncastle steals the sacred Moonstone, dies, and bequeaths the gem to his niece before the start of the novel. Rachel is young, beautiful, and from an upper-class family. She is presented as morally pure and wishes to marry for love. She ends up happily married to Franklin at the end of the novel after many plot twists and obstacles.

Sergeant Cuff

Sergeant Cuff of Scotland Yard is a professional detective who makes some headway in examining the theft of the Moonstone but initially suspects that Rachel and her maid may have colluded in its theft. He drops the case but provides valuable clues to the eventual solution. He is called back onto the case after a long interval and apprehends the real culprit.

Rosanna Spearman

Rosanna Spearman is Rachel's maid and has a criminal past. Although she is innocent of the theft, she does conceal important evidence and provide a valuable clue in a letter. She eventually commits suicide.

Godfrey Ablewhite

Godfrey Ablewhite is a villain in the story due to his concern with financial gain over human relationships. He is a key figure in the theft of the Moonstone and also an (unsuccessful) rival to Franklin for Rachel's hand.