

"Space nightmares!"
When the first manned flight to Venus returns to Earth, the rocket crash-lands in the Mediterranean near a small Italian fishing village. The locals manage to save one of the astronauts Colonel Calder, the mission commander. A young boy also recovers what turns out to be a specimen of an alien creature. Growing at a fantastic rate, it manages to escape and eventually threatens the city of Rome.
Colonel Robert Calder

Marisa Leonardo

Dr. Leonardo

Dr. Judson

Maj. Gen. A.D. McIntosh

Commissario Unte

Signore Contino - Government Official

Dr. Sharman

Pepe

Fisherman Mondello (uncredited)
Fisherman Verrico (uncredited)
Reporter Reynolds (uncredited)

Reporter Maples (uncredited)
Felix Roi, a French reporter (uncredited)

Farmer (uncredited)
Man Feeding Elephant (uncredited)

1st Reuters News Correspondent (uncredited)

Dr. Koruku - Japanese Scientist