Anna takes up her new post on Garden Key, home to Fort Jefferson, a notorious Union prison during the Civil War, after fleeing a marriage proposal from just-divorced Sheriff Paul Davidson. As she goes about her duties, Anna quickly becomes ensnared in one life-threatening situation after another. Anna's fans expect no less; all her postings somehow turn dangerous. Indeed, the contrast between the natural beauty of the landscapes and the human evils within them is a recurring theme. But this one has an added twist: a mystery concerning alleged Lincoln assassination conspirator Dr. Samuel Mudd interweaves with current crimes.