Trick or Treat provides a thorough history of this most misunderstood phenomenon. Offering a fascinating overview of how Halloween has spread around the globe, it asks how festivals as diverse as the Celtic Samhain, the British Guy Fawkes Day and the Catholic Holy Days of All Saints and All Souls could have blended to produce the modern Halloween. Halloween's influence on popular culture is examined via the literary works of Washington Irving and Ray Bradbury, films such as John Carpenter's Halloween and Tim Burton's The Nightmare Before Christmas, and television series, including Buffy the Vampire Slayer, The Simpsons and True Blood.