The Carews are a contented clerical family in the West Country, the eldest son of which is away serving in the Navy. This is the only fly in their ointment as the French are threatening England's security and the Navy is on guard. So it is to his relatives' delight that Nugent returns home; not so much to their delight, he brings a French wife with him. However, it is not long before they all find that Charlotte is the perfect wife for their beloved Nugent, so it is most surprising that one day she runs away. Eventually traced to dismal lodgings in Bath, things look bleak for the Captain's lady, under suspicion of spying. A missing letter seems the only possible rescue, and the hunt is on to track it down.