Walt Duffy was a world-renowned ornithologist, outdoorsman, and nature photographer who spent his life traveling and taking some of the most highly regarded photographs of birds in their natural habitats. Until, that is, over a year ago, when a climbing accident left him paraplegic. Now he spends his time in the backyard of his brownstone in Boston, with only his dog and his teen-aged son Ethan for company. Brady Coyne, Walt's long-time friend and...