Nanu the polar bear cub is worried. His ice slide is shrinking day by day. Mom and Grandma are worried about their home glacierits melting too. And Father Bear has been gone for days on a hunting trip.Driven by the melting ice floes, Mom and Nanu set out on a journey to find a new home. A friendly tern accompanies them as their pathfinder. But the journey is long and tiring, and ice is melting all around them. Will the polar bear family ever be reunited?