A nightmare unfolds in James Whale‘s The Invisible Man (1933):  The formula that renders Dr. Jack Griffin (Claude Rains) invisible, which is bad enough, also works against the mind.  Griffin turns into a crazed killer, something he never anticipated—responsible for the murders he commits insofar as meddling with chemistry was a bad idea.  Now all that’s left is for the authorities to destroy the Invisible Man, and director Whale is impressive at showing the single-mindedness here, and at building momentum.  I don’t know how well R.C. Sherriff’s script represents H.G. Wells’s novel, but I know how well it represents the acumen about fictional horror.  It’s an acumen Whale possesses.