In nineteenth-century Vienna, a drama of love, fate, and will is played out amid the intellectual ferment that defined the era. Josef Breuer, one of the founding fathers of psychoanalysis, is at the height of his career. Friedrich Nietzsche, Europe's greatest philosopher, is on the brink of suicidal despair, unable to find a cure for the headaches and other ailments that plague him. When he agrees to treat Nietzsche with his experimental "talking...