The Moonstone

'The first detective novel in the English language'
The Moonstone
A Romance
by Wilkie Collins
The Moonstone (1868) by Wilkie Collins is a 19th-century British epistolary novel, generally considered the first detective novel in the English language. The story was originally serialised in Charles Dickens' magazine All the Year Round. The Moonstone and The Woman in White are considered Wilkie Collins' best novels. Besides creating many of the ground rules of the detective novel, The Moonstone also reflected Collins' enlightened social attitudes in his treatment of the servants in the novel. Collins adapted The Moonstone for the stage in 1877, but the production was performed for only two months.
Colonel Herncastle, an unpleasant former soldier, brings the Moonstone back with him from India where he acquired it by theft and murder during the Siege of Seringapatam. Angry at his family, who shun him, he leaves it in his will as a birthday gift to his niece Rachel, thus exposing her to attack by the stone's hereditary guardians, who, legend says, will stop at nothing to retrieve it.
Rachel wears the stone to her birthday party, but that night it disappears from her room. Suspicion falls on three Indian jugglers who have been near the house; on Rosanna Spearman, a maidservant who begins to act oddly and who then drowns herself in a local quicksand; and on Rachel herself, who also behaves suspiciously and is suddenly furious with Franklin Blake, with whom she has previously appeared to be enamoured, when he directs attempts to find it. Despite the efforts of Sergeant Cuff, a renowned detective, the house party ends with the mystery unsolved, and the protagonists disperse.
During the ensuing year there are hints that the diamond was removed from the house and may be in a London bank vault, having been pledged as surety to a moneylender. The Indian jugglers are still nearby, watching and waiting. Rachel's grief and isolation increase, especially after her mother dies, and she first accepts and then rejects a marriage proposal from her cousin Godfrey Ablewhite, a philanthropist who was also present at the birthday dinner and whose father owns the bank near Rachel's old family home. Finally Franklin Blake returns from travelling abroad and determines to solve the mystery. He first discovers that Rosanna Spearman's behaviour was due to her having fallen in love with himself. She found evidence (a paint smear on his nightclothes) that convinced her that he was the thief and concealed it to save him, confusing the trail of evidence and throwing suspicion on herself. In despair at her inability to make him acknowledge her despite all she had done for him, she committed suicide, leaving behind the smeared gown and a letter he did not receive at the time because of his hasty departure abroad.