Werner Herzog’s gripping documentary chronicles one of the most extreme—and ultimately tragic—experiments in human-animal cohabitation ever attempted. For thirteen consecutive summers, single-mindedly devoted environmentalist Timothy Treadwell lived (and finally died) among the brown bears at Alaska’s Katmai National Park. The footage that he shot forms the core of this fascinating, unsettling, and thought-provoking inquiry into obsession and the fragile relationship between man and nature.