Branded — Kelley Armstrong

A post-Apocalyptic Otherworld story.
Rayne and Braeden live in a world decimated by war and famine, a world where survivors take refuge in fortresses, protecting themselves against a land overrun by hybrids -- the horrific results of wartime genetic modifications -- and the branded -- roving bands of supernatural outcasts. When Rayne exposes Braeden as a werewolf, she's lauded as a hero. But it's actually just the first step in their desperate bid for freedom.