There's a guy in a cave watching old newsreel film of the first two World Wars. He talks to his snake, then he watches films of the 1960s including a Woodstock-style concert, and then clips of the Vietnam war. He is clearly some sort of historian cataloguing old films, and we hear his interior monologue as he watches. This goes on for twenty minutes, about a quarter of the film's runtime.
Then he starts watching films of the Nazis at work in 1986. Ah, finally, the story appears! It seems that the Nazis made a comeback in the mid-1980s, first by killing a bunch of international dignitaries (who happen to be going across a desert in an old 1940s Greyhound bus). Their deaths are investigated by Robert Vaughn who is some sort of secret agent. He bails out of a plane and parachutes down somewhere in South America where The Nazis have set up a base. Vaughn gets chased around for a while until he's cornered by a stock footage alligator. He's captured and knocked out, and wakes up in a Florida Hospital. But wait -- it's not a hospital, it's the Nazi base disguised as a Florida hospital! Oh, those damn Nazis are clever!
But not as clever as they think as Vaughn sees through the deception, and starts kicking Nazi butt after he discovers the Nazis are cloning world leaders! And then he takes on an eighty year-old Hitler who can teleport at will, then he has to fight it out with a clone of himself!
This is awful. This is the sort of bad film that gives bad films a bad name. It's not even camp or tawdry, just cheap and silly. It's standard low-budget action fare that is plodding and unspectacular, and damn near unwatchable really. The bookends by future-film-watching-guy don't help, either.
There's a reason why this 1976 film sat on a shelf for two years before being released directly to tv: it's really bad.