The Warriors Path by Louis L'Amour

When Yance Sackett's sister-in-law is kidnapped, Yance and his brother Kin race north from Carolina to find her. They arrive at a superstitious town rife with rumors — and learn that someone very powerful was behind Diana's disappearance.

To bring the culprit to justice, one brother must sail to the exotic West Indies. There, among pirates, cutthroats, and ruthless "businessmen," he will apply the skills he learned as a frontiersman to an unfamiliar world ... a world where one false move means instant death.