A dairy farming community in northern Japan is being stalked by an unseen peril: a giant brown bear that attacks cows in the dead of night, killing some and merely injuring others. For years it has eluded teams of researchers and capturers committed to bringing it down. But what is the true nature of the beast they're pursuing? Is it one bear or several? And how have human actions helped create this situation? We follow efforts to track down the animal and to understand what led to its behavior.