In a "European" village of the late 1890's, Professor
Mayer (played by Boris Karloff) and his assistant Isabel have
created a ray machine that burns a hole through the ceiling
of their lab and attracts a flying saucer!
The aliens decide that the ray poses too great
of a threat to their kind and decide that the ray and all
who have worked on it must be destroyed.
A sex murderer in the local area is the first unfortunate
victim of the alien terror. He becomes possessed by an
alien intelligence and proceeds to infiltrate the Professor's
Eventually, the Professor himself is then taken over by
an alien mind transference. The alien "Professor" then rigs
the ray gun to self-explode. A battle of wills then ensues
(mostly that of the audience trying to remain awake).
The Professor eventually throws off the alien intelligence
but realizes that the ray is too powerful for human
use, and he destroys the ray gun himself. The aliens depart.
The house burns down.
Supposedly influenced by HPL's "The Thing on the Doorstep".
This gem was filmed in Mexico and was one of Karloff's last