Still, she felt the call, and once she qualified to train a dog of her own, she adopted Puzzle, a strong, bright Golden Retriever puppy who exhibited unique aptitude as a working dog but who was less interested in the role of compliant house pet. Puzzle's willfulness and drive, both assets in the field, challenged even Susannah, who had raised dogs for years.

Scent of the Missing is the story of Susannah and Puzzle's adventures and of the close relationship they forge as they search for the lost -- a teen gone missing, an Alzheimer's patient wandering in the cold, signs of the crew amid the debris of the space shuttle Columbia disaster. From the earliest air-scent lessons to her final mastery of whole-body dialogue, Puzzle emerges as a fully collaborative partner in a noble enterprise that unfolds across the forests, plains, and cityscapes of the Southwest. Along the way, Susannah and Puzzle learn to read the clues in the field, and in each other, to accomplish together the critical work neither could do alone and to unravel the mystery of the human-canine bond.