I haven't read the book, but isn't it kinda non-linear and epistolary in structure? Those are always an intriguing read. The movie is really a lot of fun. I liked the history/horror mashup. I only wish they'd picked some other battle than Gettysburg for the big climatic thing. In a war of 10,000 battles and skirmishes, you'd think someone could fictionalize something other than those 3 days. There's a fun collection of sci-fi stories called "Civil War Fantastic" that's a great read but every other story is set in Gettysburg.