The Final Silence by Stuart Neville Soho Press, Inc., $26.95, 340 pages, ISBN 978-1-61695-548-9 If you think about it, all of us have two faces. The first is the one we show to the world and the second is our private self—the inner person—the person we truly are, where our secret interests lie. Usually they’re harmless enough . . . a dedicated coin or stamp collector for instance, maybe