A Fine Line - William G. Tapply

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 attorney, handles his routine legal affairs and is asked by Walt to deliver a set of Meriweather Lewis letters to a rare book dealer for authentication. Shortly after, responding to a call from Duffy, Coyne stops by after work only to find Walt dead - murdered - in his backyard. Robbery is dismissed as a motive when the only thing that turns up missing is Walt's laptop. Equally disturbing is the fact that Ethan, Walt's son, is missing without a trace, any sign of struggle, or any clue to where he may have gone. There is also evidence that Walt was somehow involved in a notorious eco-terrorist group that is currently taking deadly action around the Boston area.

With the FBI and the Boston police watching him closely, the eco-terrorists escalating dramatically, and Ethan still missing, Brady finds himself in the center of an increasingly dangerous plot. With the death toll mounting, Brady realizes he has to find the missing Ethan and unravel the complex puzzle before either of them becomes the latest victim.