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.