It was the eighth novel in the series, though it is set earlier than the others, at the start of the career of Richard Bolitho.

The book opens with Richard Bolitho arriving at a Portsmouth inn frequented by midshipmen.

Sailing towards West Africa, they encounter an empty merchantman, City of Athens.

Dancer and Bolitho are sent aboard the ship and discover that it has been pillaged and the crew killed.

In company with the captured City of Athens, Gorgon approaches a coastal fort surrounded by treacherous reefs and shoals.