code: def _fly(self, board, layers, things, the_plot):
      
      # Disappear if we've hit a bunker.
      if self.character in the_plot['bunker_hitters']:
        return self._teleport((-1, -1))
      # End the game if we've hit the player.
      if self.position == things['P'].position: the_plot.terminate_episode()
      self._south(board, the_plot)
docs: Handles the behaviour of visible bolts flying toward the player.