While many armed rebels around the world are driven by extreme ideas, one elusive armed group is fighting for democracy — the Sudan People’s Liberation Movement-North. Nicholas Casey, a New York Times Magazine reporter, and Moises Saman, a photographer, embedded with the group in territory it runs amid the civil war ravaging Sudan. As many as 150,000 people might be dead, and millions are displaced, though the chaos has made an accurate count impossible. As the rebels eye the next city to “liberate,” in their words, they seem more equipped for battle than for defending their people against a famine hurtling towards them.