The story is told from the point of view of an inexperienced nineteen-year-old girl, Kerenza Vyvyan. Her voyage on the packet ship Kestrel is not only a journey to ransom her mother and sister held captive by the Governor of Tangier but also proves to be a journey of self-discovery. Kerenza bravely faces the various disasters that befall her on board with a growing strength of character and fortitude she never knew she had.
Jane Jackson's heroine, Kerenza, prefigures the feisty women of 20th century novels rising above the traditional role mapped out for a woman of her time. However, this is not all action and adventure for during the course of her travels Kerenza regains the love and trust of Kestrel's captain, Nick Penrose, who had broken her heart earlier.