Liz Bonnin looks back on one of her most memorable adventures in one of our last great wildernesses, Siberia, helping a team of scientists out in Ussuriysk to locate a population of rare Siberian tigers. Gordon Buchanan recounting the time he went to Ellesmere Island, Canada in search of wild wolves that had never seen humans before. Chris Packham remembers the time he ventured to Greenland on an expedition to uncover the secret life of an Arctic iceberg. Finally, Steve Backshall recalls trying to get underwater with a killer whale in northern Norway, one of the few wildlife encounters that had eluded him across a 20-year career.