With his sun-bronzed skin, a week’s worth of beard, and a shaman’s crystal around his neck, Will Sanchez Travers looked more like a man mothers warned their daughters about than a Harvard-trained ethnobotanist. And even if only half the rumors about him were true, Dr. Annie Parrish figured she was in trouble. Still, she needed the rogue scientist to ferry her upriver in search of a prize so extraordinary, it would make her reputation–if it didn’t get her killed first.