Directed by Bill Rebane and an uncredited Herschell Gordon Lewis, Monster A Go-Go has astronaut  Frank Douglas (Henry Hite) — or maybe an alien impersonating him — coming back to Earth and going wild, often being restrained by scientists, not that anyone sees it. Most of the movie seemingly must be inferred from dialogue or read by the narrator. Rebane gave up on this movie in 1961 and Lewis came back to finish it, as he needed something to show along with Moonshine Mountain. Characters disappear, never to return. There is nothing resembling normalcy.

The movie ends with this narration: “As if a switch had been turned, as if an eye had been blinked, as if some phantom force in the universe had made a move eons beyond our comprehension, suddenly, there was no trail! There was no giant, no monster, no thing called “Douglas” to be followed. There was nothing in the tunnel but the puzzled men of courage, who suddenly found themselves alone with shadows and darkness! With the telegram, one cloud lifts, and another descends. Astronaut Frank Douglas, rescued, alive, well, and of normal size, some 8,000 miles away in a lifeboat, with no memory of where he has been, or how he was separated from his capsule! Then who, or what, has landed here? Is it here yet? Or has the cosmic switch been pulled? Case in point: The line between science fiction and science fact is microscopically thin! You have witnessed the line being shaved even thinner! But is the menace with us? Or is the monster gone?”

Most horror movies end with the monster chased down and killed. This one ends with Lewis reading those words, probably because that was cheaper. You have to admire that.

You can watch this on YouTube.