A Royal Navy frigate, HMS Rutland, is conducting a scientific experiment when something goes terribly wrong, and they find themselves with no engines and confronted by a Royal Navy sloop from 1805. Julia Mitchenson, the Captain of Rutland, and Charles Austen, of HMS Indian combine to destroy a French frigate and outwit the powerful Invisible squadron in a race to reverse the time slip. Julia and Charles are drawn to each other, as are Lt Benna Garret and Lt William Mends. The story combines the sly humour of Patrick O'Brien and the social observation of Jane Austen in a gripping and well-researched story that has action, romance and more than a touch of science fiction.