As a sympathetic—and brilliant—brain detective, Harold Klawans treated people with a huge array of troubles, all of which boiled down to one complaint: something was wrong with their brains. From the woman suffering from "painful foot and moving toe syndrome" to the Indiana farmer who contacted a variant of mad cow disease from his herds of livestock, Klawans deduced a great deal from his patients, not only about the immediate causes of their ailments, but about the evolutionary underpinnings of their behavior.