This is a remarkable movie in many ways. With a relatively small budget a very interesting Sci-Fi / horror film is made. No big visual effects, no Big Stars in the cast, black n' white photography and still a griping story. There are two remakes of this story, they can't stand against the original one, even if they were produced with a bigger budget and known actors.
This is the plot: Dr. Bennell (Kevin McCarthy) returns to his small home town ready to attend patients. Different consultants tell him of a paranoid syndrome: their relatives seem somehow changed. A couple of days after that, they return to his office and tell him "Everything is OK".
Dr. Bennell and her old times girl friend Becky Driscoll (Dana Wynter) soon realize the town is being subject to an alien invasion plot. Huge seed are "planted" in basements or garages and evolved in a duplicate of a person (a clone will be called today). As soon as the victim fells asleep is "transformed". The tension grows up as time pass and the characters need to sleep.
Some comments issued around the film pointed out that it may be taken as a parable of the Cold War raging at the time it was released (1956). I think that there are more films of that period, alluding the frightful issue of "They are like us but they are NOT us and they are dangerous", as in "The Thing from another World" (1951) or "I Married a Monster from Outer Space" (1958).
The actress Carolyn Jones (later best known by her impersonation of Morticia at the "Addams Family" TV serial) play a short, but very well enacted, role
A very enjoyable film to be seen.
Duration: 80 minutes