I first became aware of the Alfred Dreyfus case when I watched a film, "The Life of Emile Zola." I then talked with my husband, a military history buff, about the matter and found him highly informed. That began my fascination with the framing and false imprisonment of the Jewish military officer.
Robert Harris takes us straight into the case, with a well-researched novel (Dreyfus' own writings, and transcripts of court testimonies, inform the tale), which is told from the perspective of Georges Picquart. Picquart is an actual historical figure, who became obsessed with proving Dreyfus' innocence in the face of incredible anti-Semitic opposition. (An excellent article on Picquart may be found here.)
We see Picquart from his earliest days in Intelligence, rising to Minister of War, all the while working to prove that his fellow officers had sent the wrong man into exile on Devil's Island. Harris gives us a Picquart who is flawed in many ways himself, but whose sense of military honor will not allow him to remain silent -- even when silence would preserve his own career.
I would recommend this book for military history buffs, Francophiles, and even those interested in matters of social justice.