A group of scientists (which we know are serious scientists as they have white coats on) are trying to build a window into time. However, they discover their window is actually a portal into the future. Danny (Steve Franken) - who is in overalls and so not a scientist of course - steps into the portal. He is followed by Scientists Steve (Philip Carey) and Dr von Steiner (Preston Foster). Carol (Merry Anders) meanwhile is tasked to keep an eye on the portal, but as she is a 1960s ditzy female (despite being a scientist) she of course also steps through the portal and ends up marooned in a desolate future along with the rest of them.
On the run from a gang of mutants, the scientists and Danny are saved by the last survivors of human civilisation. Dr Varno (John Hoyt) explains that the Earth was turned into a wasteland by nuclear war, now final preparations are being made to launch a space ship to take them to Alpha Centauri...
Not the worst 1960s science fiction movie, the story has a little bit more sophistication than usual. The film lacks much in the way of action and can be a little dull at times. The goofy humour was probably included to counter that, though does not really work very well. The budget was low but they made the most of it.