The British cruiser Ariadne is on the East Indian station. Her mission: to intercept Arab slave dhows and free the wretched African slaves that are being taken from East Africa to be sold on slave markets in the Middle East.
On board the Ariadne is midshipman Everard Brooke. When they are in port in Muscat some disturbing intelligence reaches him. The ship's interpreter Hassan has heard that two dhows full of slaves are on their way to Arabia...