Bestselling author Bear Grylls has survived a free-fall parachute accident that left him with a broken back, possibly unable to walk again; falling down a mountain in the Rockies, severing a finger in the Vietnam jungle, a broken shoulder in Antarctica. He passed the gruelling training to join the SAS, crossed the North Atlantic in an open inflatable boat, and held the highest ever open-air formal dinner party, in a balloon at 25,000 feet.