Kaspar Almayer is a young Dutch trader taken under the wing of the wealthy Captain Lingard. Hoping to inherit Lingard's wealth, Almayer agrees to a loveless marriage to Lingard's adopted Malay child and to running his trading post in Sambir in the Borneo jungle. Lingard loses much of his fortune searching for a hidden treasure. Meanwhile Almayer's ventures constantly fail, most notably an expensive trading house, the "Almayer's Folly," that no one trades in.
A daughter named Nina was born to Almayer and his wife. The rest of the novel concerns Almayer's conflicting desires: his love for Nina, his effort at keeping her from her mother's Malay influence, and his desire for money and self-redemption.
Dain, a Malay prince, arrives at Sambir. Almayer tries to enlist Dain's help to find the treasure long sought by Lingard. Instead, Dain marries Nina and leaves Sambir with her, against Almayer's wishes. The loss of Nina and any prospect of wealth stuns Almayer. He spends the rest of his days in the empty trading house as his sanity slips away.
