The BBC's world-renowned Natural History Unit has brought the marvels of the planet to millions of viewers using breathtaking photography and pioneering filming techniques. Natural World is their award winning flagship series that presents surprising wildlife stories from across the world. This is the incredible story of a dedicated naturalist who raises orphaned grizzly bear cubs by hand in eastern Russia. For ten years Canadian Charlie Russell has been raising orphaned grizzly cubs in the Russian wilderness of the Kamchatka peninsula, an area of heart-stopping beauty, filled with volcanoes and geysers, pristine forests, lakes and salmon streams - and home to the densest population of brown bears in the world. Becoming the cubs' surrogate mother he struggles to keep his cubs alive and teach them everything they need to survive a life in the wild. The incredible film follows Charlie as he raises four new orphaned cubs, spending nine months living with them as they become increasingly independent and make the crucial transition to the wild But will he be able to keep them safe from other grizzlies and the ever present threat of poachers?