“Maggie’s long German shepherd nose had more than two hundred twenty-five million scent receptors. This was as many as a beagle, forty-five times more than the man, and was bettered only by a few of her hound cousins. A full eighth of her brain was devoted to her nose, giving her a sense of smell ten thousand times better than the sleeping man’s, and more sensitive than any scientific device. If taught the smell of a particular man’s urine, she could recognize and identify that same smell if only a single drop were diluted in a full-sized swimming pool.”