Summer 1795: Roger Ellis is a newly promoted naval lieutenant who finds himself unexpectedly beached on shore and unable to secure a new berth. When Roger, a keen student of modern philosophy, and especially the European philosophy of enlightenment, is obliged to stay in London to be close to the Admiralty, he finds it hard to settle into a society which he sees as louche and self-centred. So, when he is encouraged by his friends to take a break from the city, he happily returns to his home village of Canewdon, an isolated place set deep within the Essex marshes, from whence he left at the age of twelve to go to sea. Roger soon finds that the village is not quite as idyllic as he remembers, but when he reconnects with Elizabeth Saunders, a childhood friend now grown to be a beautiful but slightly wild young woman, it begins to look like this summer may be one of the most memorable of his life. As the weeks fly by Roger is drawn ever further into a hitherto unknown and totally unsuspected world of romance, superstition, sexuality, and danger that may well change his life forever.