Not Rated | | Horror, Sci-Fi
After landing on a mysterious planet, a team of astronauts begin to turn on each other, swayed by the uncertain influence of the planet and its strange inhabitants.
Susan Hart was originally cast as Sanya, but upon arriving in Rome immediately following her honeymoon with AIP co-founder James H. Nicholson, she was locked out of production due to Samuel Z. Arkoff's enforcement of a new anti-nepotism company policy. Hart also suspects that Barry Sullivan's on-set arguments with an unidentified production member was another factor in her dismissal. Norma Bengell was not cast as her replacement until halfway through shooting. Hart would later appear in another Mario Bava film, Dr. Goldfoot and the Girl Bombs (1966), although her only scene in the film was recycled from its prequel, Dr. Goldfoot and the Bikini Machine (1965).
Capt. Mark Markary:
One entire crew lost; two of our own crew gone. Bert dead, Eldon disappeared. And this unknown enemy keeps getting closer!
Dr. Karan: The enemy is also becoming visible.
Capt. Mark Markary: What do you mean by that?
Dr. Karan: Well, you saw something. Something not quite identifiable out of...
When the 2 astronauts are peering through the door to recapture the Meteor Avoider; a film crew's shadow can be seen, and retreating on the left wall.
The original Italian version runs 88 minutes long. The US version runs 86 minutes long.