Three young bears of different species--one black, one polar, and one grizzly--travel on a perilous quest to the Northern Lights, escorting a shape-shifting grizzly cub whose destiny will affect them all.

The four bears finally arrive at the legendary Last Great Wilderness, thinking it is the end of their long journey, but they discover that their true mission has really just begun.

At the edge of the Endless Ice, the four bears Ujurak, Toklo, Lusa, and Kallik reach Star Island, where a large group of bears is in trouble but believes Lusa is destined to help bring back the favor of the spirits.