Joanna Ramsey and her crotchety scientist father, Captain John Ramsey, are hiding out in their secluded mountain valley house while WWIII happens. She's bummed because her boyfriend, Steve, never made it in time and is most probably dead. But two brothers soon show up, one of them exposed to the high radioactivity. The other is clearly a potential boyfriend for Joanna. Then, another couple appears, a hoodlum and a red-headed dancer. They represent the bad part of society, obviously. The next to appear is a nearby rancher who is still making moonshine.
To explain how they have all managed to survive, the father takes out a convenient diorama and explains that it's due to a combination of them being in a valley surrounded by lead ore, protected by the mountains and the wind currents. He also tells them, prophetically, that "they'll live or they won't". He also makes it clear that he's the number one guy in charge, though there's not much he can do to enforce it. He constantly walks around with a geiger counter which makes little sense since he already says that they are protected in the valley.
Then, we see a mutant walking in the nearby forest. Around this time the one guy's brother wakes up and says he can hear game in the surrounding forest. And although it's radioactive he can eat it. He craves raw, red meat...and in the next few days he begins to become more animalistic. There's also another manlike creature, half dead, that stumbles near there house and he's even more mutated. Before he dies he says he "wasn't strong enough, like the others". Others? Can there be a huge group of ugly mutants on the other side of the valley?
Three weeks later they are all still breathing and smoking cigarettes. By now there is a new mutant spying on them, which has a psychic connection with Joanna. It turns out to be her missing boyfriend Steve, transformed into a hideous creature with a bulging white eye. But all is not lost. It begins to rain. This should be contaminated with radioactive fallout--but it's clear--and because it's pure the water starts killing all the new mutants, basically washing all the bad stuff away. La la la...
An inferior remake of Roger Corman's THE DAY THE WORLD ENDED (1955). Directed by Larry Buchanan.