Somewhere in the world, there is a collection of books. Perhaps it's in a dusty, unpainted shelf in the back corner of someone's attic; maybe it's in a set of musty boxes in the basement of some tiny, obscure library. It contains a few hundred volumes, all handwritten, ranging from leather-bound volumes with yellowed pages two hundred years old to modern spiral-bound notebooks. All of these are diaries, some by famous people, some by not-so famous people, but all by the most horrific madmen and murderers the world has ever known.