Chicago, Illinois, is a historic city filled with mystery. In these pages, you will learn about some of the most famous Chicago mysteries that, to this day, still have no answer. Who caused the Great Chicago Fire of 1871? Read about Al Capone and the Valentine's Day Massacre, the Smiley Face Murders, and the many people who have gone missing. From the very beginnings of the city to today, mysteries abound within the Windy City. People disappear, UFOs are spotted over O’Hare International Airport, pranksters interrupt television broadcasts, and the bodies of a notorious serial killer’s victims are still being sought. All of these tales, and more, are here to tantalize your mind, haunt your dreams, and keep you guessing.