S1, E1: Taller than Shaquille O'Neal, he could kill a human with a single swipe of his paw. He is an 800-pound grizzly bear named Brutus, and the curious companion to renowned naturalist Casey Anderson, who has raised him since birth. Casey has dedicated himself to wildlife preservation and takes a daring approach to understanding grizzlies' every move-living among them and observing their behaviors, and even tasting some of their favorite foods. Together, they set out on a year-long mission to chronicle the lives of Yellowstone's vulnerable grizzly bears-mysterious beasts that have elicited fear and respect among humans through the ages. Filmed in stunning HD in some of Yellowstone's most treacherous and remote terrain, their unique story is an awe-inspiring glimpse deep inside the grizzlies' wilderness.