These are some of the names that strike terror into even the bravest of hearts. Human monsters, they preyed upon the unsuspecting, freely feeding their terrible hungers. Their crimes were unspeakable, as they maimed, tortured, killed, and killed again, leaving so many dead in their bloody wake. But somehow, astonishingly, seven would-be victims fell into the clutches of the century's worst serial killers—and escaped death through courage, divine providence, or just plain luck.