A lost "classic"? A "long-sought horror gem"? Nawww! This is just a crappy little monster movie shoved out to drive-ins by a confused 20th Century-Fox no longer run by Darryl Zanuck. Fox had the knack back then to put out some of the most miserable, boring little b-films in various genres. Somebody thought THIS was worth making. Then again, at only an hour in length it didn't cost much in film stock. The cast came cheap, too, as did the effects. Poor John Agar could only get star parts in horror films and must've figured it was worth taking any part as long as he was top-billed. Unfortunately for him, he spends the second half of the film encased in a bulging, grotesque Halloween costume and is never seen again (there's not even the cliché deathbed return-to-normal moment). In fact, his voice is gone as well, reduced to a series of muffled, unintelligible growls and cries (for all we know he's yelling "get this monster mask off of me, I can't breathe!" or "I'm calling my agent!") Is it no wonder he virtually drank himself out of the business? And then there's that atrocious score by Sonny Burke, an otherwise successful producer-arranger of contempo music (Sinatra, etc.) Burke wallpapers the first part of the film with shrill organ and theremin noise, then tiring of that, decides to add bongos and bassoon-like honking to the mix, for a combination you could describe as 'Horror-Jazz Fusion.' A lethal cocktail for the ears, unless one is in search of bad scoring just for the laughs.
Plotwise it's the story of scientist who unleashes a gas upon himself that makes his touch lethal and his mind insane, and the only response to that is for him to spend the rest of the film running madly around town avoiding medical assistance. Coincidentally, this film's effect upon the viewer is the same as its story: A lethal gas that makes you insane and want to run madly in the streets trying to avoid any further contact with it.