You really can't appreciate Planet of Prehistoric Women (PoPW) if you don't know its roots. As you will have read in other reviews, much of PoPW is made out recycled footage from Voyage to the Prehistoric Planet (VPP). VPP itself is the English dubbed version of the 1962 Soviet film "Planeta Bur" (Planet of Storms). I managed to get copies of all three and watch them in chronological order. As a fan of 50s and 60s sci-fi, it was a great experience.
A foundational "fact" which many overlook is that a very early theory about the solar system presumed that it formed from the outside in. The further planets were older in their "evolution" than the inner ones. Hence, Mars is often depicted as an older "dying" world, with an ancient civilization which seeks escape (usually to earth). Venus, in that vein of thinking, was younger than earth, less developed. Hence the idea that you'd find dinosaurs, volcanoes and primitive beings (the lizard men, not the blonds). The woman were theorized to be the feral remnant of failed colony of an advanced people who came to Venus from "out there..."
First off, the primary donor film, Planeta Bur (I had an English subtitled version) is much more of a "A" grade sci-fi film. Given that it was produced in 1962, it was a pretty strong effort. Much more akin to Forbidden Planet than Plan 9. The sets and effects are a huge step up from the B-grade stuff of the late 50s, early 60s. The rocket interiors, the seriously industrial robot, and the very cool flying car, were not low budget products.
Since the premise of PoPW is that it's a flash back, reuse of the Planeta Bur (PB) footage works. In fact, the premise of PoPW is that it's a sort of parallel story to that of PB (and by extension, VPP). In PB the cosmonauts only hear the mysterious female voice singing -- except for the little sculpture of a woman's face that Alexes finds at the last. PoPW explores that other side of the story.
Interspersed with the original PB footage (still using its English dubbing via VPP version), are new clips of the women we never see in PB. Now, I grant you they're an obvious sop to the teenage boy movie goer. They're all 20-something beautiful blonds. But, look past that. They represent the remnant of the lost civilization which the cosmonauts in PB hypothesized about. The blonds eating raw fish and worshiping a pterodactyl statue peg them as primitives -- even if remarkably well groomed.
The women in PoPW are cast as the cause of some of the cosmonaut's disaster situations: the volcano, the flash flood, which were unexplained in PB.
What continues to be left unexplored is the source of the mysterious singing voice. In PB and the English remake VPP, the mystery voice saves the cosmonauts, giving warning cries to bring rescue from the tentacle plant, etc. The women in PoPW are cast as agents of mischief, so are not that protectress (who is seen at the end of PB reflected in a rocky pool).
A curious feature of PoPW is that it splices in even more footage from yet another Soviet sci- fi film than VPP did. The rockets are completely different, but clearly still Soviet. The big red star on the tail fin is hard to miss. I've not located this other old film, but it looks cool too.
Some details within PoPW make it interesting. One is "Marsha". In PB, there was a female cosmonaut named Masha. She stayed in orbit and was the love interest of the square faced cosmonaut. Hers was a minor foil role. In VPP, she was replaced altogether (not simply dubbed) with new footage of Faith Domergue acting out the exact same role. Faith's name, along with Basil Rathbone's, had more marquee power. However, in PoPW, even Faith's footage is dropped. Instead, we're told (only once) that "Marsha" is a nickname for mission control. This is to explain the cosmonauts often calling to "Marsha" for information, etc. A bit lame.
One scene in PoPW makes no sense w/o knowledge of the prior films. When the cosmonauts think they've lost contact with earth, the square-faced cosmonaut cries out mournfully, "Marsha, dearest Marsha..." Obviously a bizarre response for not hearing from mission control, but not if you've seen PB. Just a little of the original leaking through.
Watch PoPW with an open mind. If you can, watch PB first, then VPP, then PoPW. Yes, it's a low-budget movie that (like many B-films) used prior footage to pad itself out. Here, however, instead of stock military footage, Corman used obscure Soviet A film footage. That keeps PoPW above the truly banal B films of the 60s.
