On beyond Horla

The Horla is too strange to be perceived by human sense, but that’s not the only way a monster can be invisible. In Ambrose Bierce’s short story “The Damned Thing” (1893), two hunters encounter a huge monster they cannot see. One explains the reason: “There are sounds that we can not hear. At either end of the scale are notes that stir no chord of that imperfect instrument, the human ear…As with sounds, so with colors.…The human eye is an imperfect instrument; its range is but a few octaves of t...