Charlie Hench has set himself a big challenge before he turns the big 50 - to fulfil his dream of a late-summer solo hike through the Sierra Nevada Mountains. But he underestimates the challenge ahead. Charlie is at 9,000 feet when an early snowstorm suddenly blows in. The amateur hiker is soon out of his depth, lost in the snow-covered landscape. A missed step on the treacherous boulders and he's crashes over the side of the mountain. Only a ledge, the size of a car bonnet, saves him from falling 500 feet to his death.