Adapated from H.G. Wells's story, Jack Griffin (Claude Rains) is a scientist who has successfully created an invisibility serum after testing it on himself. The rest of the film shows Griffin going slowly mad as he tries to find a way to reverse its effects.
The invisiblity effects still hold up today, and James Whale directs this film with the same wonderful flair for black humor that he brought to both Frankenstein & Bride of Frankenstein.
A pity Memoirs of an Invisible Man & Hollow Man weren't this good.