Doctor Paul Holliston (Rock Hudson) is driving home late one stormy night when his too-fast speed causes an accident: he hits a dog that was crossing the road. He stops and gets out to see if the dog can be saved, and bundles the animal into his car, rushing home to his lab. When it becomes clear that he won't be able to save it, there is a chance that he can rescue its pups, for the dog was pregnant, and it just so happens that Hollister's work involves growing foetuses outside of the womb. One puppy survives, growing at an incredible rate - but how could this translate to humans?
Yes, it's Frankenstein time again, with Hudson the unlikely doc, but the dog he grows, called Number One for obvious if not exactly conventional reasons, is not his monster. We do have our suspicions about it, however, when the hound develops super intelligence and a habit of picking up small yappy dogs in its teeth and shaking them to death, or at least shaking fluffy toy dogs in a breakdown of convincing special effects. So now we have established that if you grow a foetus outside the womb then they will have, I dunno, no soul or something, not that there is any basis for this plotline in science.
Don't listen to what that opening credit caption says, the closest this gets to science is featuring Dr Joyce Brothers as herself in a party scene, and she is a psychologist, not a human research biologist. Yes, this is schlock all the way, and director Ralph Nelson wishes to make us feel every crawling minute of the heinous experiments Dr Rock is conducting by spelling every development out wearingly literally. Inevitably our misguided hero hears about a suicide victim dying in hospital who as luck would have it (for Hollister) is pregnant, so it's time to appropriate the unborn baby and get to work.
Work being putting the foetus in a tank of water and waiting until it looks suitably full-grown baby-like. From then, Hollister's experiment has him placing the still-maturing child into an incubator and playing her self-help tapes until she has turned into beautiful genius Barbara Carrera who picks up the basics of the modern world fairly quickly, speaking, wearing clothes, counting, that sort of thing. Hollister's sister-in-law and housekeeper Martha (Diane Ladd) - his wife died in an automobile accident - is suspicious about where Babs, here named Victoria, has come from, and the doc has to invent a story about her being his research assistant.
Martha still doesn't entirely believe it, especially as Number One has taken an active dislike to her and growls every time she is near, an obvious sign that there is something against nature going on, and also an obvious sign that when we eventually get around to the expected rampage, Martha better watch her back with the nightmare couple of Victoria and her dog in the area. Before we get to that stage, there are bits of business with Victoria beating Roddy McDowall at chess (well, she lets him win, but he is furious anyway) and sleeping with Hollister in a patronising wish fulfilment plot twist, which foreshadows the ridiculous shock ending. The trouble with this isn't that it's trash, it's that everyone making it seemed to take it all painfully seriously, and couple that with a TV-movie approach you get a film that all too rarely turns into the laugh riot it constantly threatens to do. Music by Gil Melle.