Quatermass and the Pit (1967)

Quatermass and the Pit (1967), directed by Roy Ward Baker.

This is the one people seem to remember. The first color Quatermass is a Hammer remake of a 1958 TV series of the same name. Aka Five Million Years to Earth.

Construction workers discover fossilized human remains under London. They then uncover a strange object and call the bomb squad (always the cavalry in British pictures, for obvious reasons). It turns out to be a Martian spacecraft millions of years old. As it comes alive we see strange phenomena and people start changing. The area has always been a spooky, paranormal hot spot, with strong suggestions of the diabolic. The combination of straight science fiction with the dread of ancient evil builds to a dynamite climax.

Quatermass is played differently here: he's honestly afraid of what he discovers and is vulnerable to Martian mind control. As always, and fortunately for us, the Martians left a hole in their defenses that the feeble earthlings can exploit.

Slow buildup as the clues accumulate but that is part of the fun when the audience is ahead of the characters ("Don't go down there, fool!"), although the squabbling bits with the bureaucrats tend to drag. We have a pretty female scientist but no romance subplot.

Something that struck me when I first saw this on TV as a boy were the closing credits, which are presented against the background of two survivors in the wreckage. They are just staring, gasping and trying to recover, but otherwise doing nothing. At the time it seemed to me that this was meant as an ominous postscript, that after the Martian influence was destroyed the human mind was also deactivated to some degree. But now I'm not sure.

Available on region 2 PAL DVD. The region 1 NTSC versions seem to be out of print and are expensive on the used market.