Terrific little British gem from the late 1960s (based on the 1958 BBC television production) brings together the London Underground (Which is not a political movement, Otto. I looked it up.), legends of devils and hauntings, neanderthals, race memory and the Red planet.
It was released in the United States under the title of "Five Millions Years to Earth" and was produced by "Hammer Films", which was notable for it's lean and efficient film-making and it's "Hammer Horror" films, which dominated the horror genre from the 1950s until the late 1960s.
So is this a horror film? Well, all I dare reveal of the plot is that "Quatermass And The Pit" begins with a skeleton and ends with a Trump rally...
...so watch and enjoy and have a very Happy Halloween!