Park ranger Anna Pigeon is on temporary assignment at Dry Tortugas National Park, 70 miles off Key West in the Gulf of Mexico. The park contains Fort Jefferson, erected in the mid-1800s and was used as a Union prison in the Civil War. Bored at this lonely outpost, Anna becomes fascinated by letters her sister sends her that have been in their family for years. They were written to their great-great-grandmother from her sister Raffia. Raffia was married to the Union officer in charge of Fort Jefferson when it was a prison, and her letters describe the tumultuous times when she lived at the Fort.
But real life intrudes when a ranger goes missing and the little band of park employees are thrown into the search. Things get even stranger when Anna begins to "see" things and wonder about her sanity.
Barr is no stranger to the job of park ranger, and her descriptions of the parks and the rangers' work is as interesting as the plots of her novels. The author mixes history, through the letters, into the present, as Anna strives to uncover what surrounds the mysterious happenings at the park. Anna is at her best here, on her own, determined to do her job to the best of her ability. (Feb., 400 pp., $24.95)