How “The Blair Witch Project” changed horror films

IF YOU WANT to scare people, it helps if they believe the tale is real. Mary Shelley opened her novel “Frankenstein” (1818) with a series of letters. Bram Stoker put diary entries and newspaper clippings into “Dracula” (1897) to increase its authenticity. But it was “The Blair Witch Project”, released 25 years ago in July 1999, which most convincingly muddled fact and fiction. In the process, it became one of the most important horror films of all time.