Nine years after being blown up in Afghanistan, one of Britain's most wounded soldiers takes on a gruelling mission to canoe hundreds of miles down Canada's mighty Yukon River. Ben Parkinson from Doncaster, had both legs amputated and was left with a severe brain injury after the explosion in 2006. Medical staff warned Ben that he might never walk or talk again - but he's defied the odds to take on an expedition down one of the world's most remote river systems. All that stands in his way are bears, wolves and rapids - and the battle with his own damaged and broken body.