In the 1870s, supporters of the pretender to the throne of Spain take advantage of a young man's attraction to the sea to persuade him to run dangerous missions on their behalf, with the financial support of a beautiful but exceedingly baffling young heiress, with whom the young man is soon giddily in love. Told largely in the first person, the novel is unusual, for Conrad, in focusing largely on the evolving psychology of a young man in the throes of a great romantic passion. (Summary by Peter Dann)