In 2014, Dylan Farrow, Woody Allen’s adopted daughter, wrote an open letter on a New York Times blog. It was a sickening account of alleged abuse. It was terrifying, eloquent and desperately sad. It culminated in a sordid assault: “When I was seven years old, Woody Allen took me by the hand and led me into a dim, closet-like attic on the second floor of our house. He told me to lay on my stomach and play with my brother’s electric train set. Then he sexually assaulted me.”