Their magic tree house takes Jack and Annie to the Arctic, where a polar bear leads them onto very thin ice.

Sophie is uninterested in writing a research report on polar bears until a polar bear named Olafur swoops her away to the Arctic, where she learns all about the playful bear's habits and habitat, from glacier mice to Northern Lights.

With no word from his missing brother Max, Jack Stalwart can only think the worst when the director of the Global Protection Force summons him to its top-secret headquarters in the Arctic Circle. Jack's informed that a team of scientists has vanished and the director wants his best agent on the job.

In searching for the source of the special music he hears, Snowbear meets and befriends the whale Uugah Beluga, who teaches him to sing.