The walrus is one of the Arctic's most enigmatic animals. With three-foot-long tusks and a droopy mustache, everyone knows what these marine mammals look like, but few ever see them in the wild. For Kirk Johnson, a paleontologist and Sant Director of the Smithsonian National Museum of Natural History, the walrus has been a creature close to his heart for 40 years. Most of the world's walrus, about 250,000 of them, live in the frigid seas between Russia and Alaska. Johnson embarks on an Arctic adventure to uncover the hidden lives of these lumbering giants and the threats they face as climate change shrinks the sea ice. He follows the fate of one young orphan, who is rescued and rehabilitated at the Alaska Sealife Center. What kind of future lies ahead for her and for the walruses in the wild?