The Invisible Man Returns

After being wrongly convicted of killing his brother, Geoffrey Radcliffe (Vincent Price) faces a death sentence. But Dr. Frank Griffin (John Sutton), whose brother invented an invisibility potion, helps Radcliffe flee prison by injecting him with the serum. Unfortunately, the serum has a nasty side effect: it slowly but surely leads to insanity. So while Radcliffe is now free to find the real killer, he also is in a race against time -- unless Dr. Griffin can invent an antidote before it's too late. (official distributor synopsis)