In 1890, a European scientist invents a ray machine which runs on nuclear power attracting to Earth a flying saucer with mind-possessing aliens who want to destroy the device before it can threaten the universe. The main alien takes over the mind of a sex serial killer to use as his slave.

As with the other three American-Mexican Karloff outings, this isn't highly regarded. It's not that bad a film but the great actor probably could have deserved something better to bow out with.

Released in a truncated version as Alien Terror on VHS.