Soldiers in the Scottish Highlands are conducting manoeuvres in the countryside, the superiors teaching the troops to find radioactivity buried in a muddy field with a Geiger counter. When it looks as if they have all had their shot, it turns out not to be the case because one soldier complains he had not had a go, so amid much grumbling the canister is buried once again and off he goes. However, he has some trouble, due to the sudden increase in radioactivity in the area: that canister has attracted something from beneath the earth... something deadly.
In Britain during the nineteen-fifties the most influential fictional name in science fiction, and horror for that matter, was Professor Bernard Quatermass, the scientist dreamt up by writer Nigel Kneale for a wildly popular television serial. The low budget production company Hammer seized their chance to get the rights for the movie version, which turned their fortunes around and made them the byword for British horror movies across the world, but Kneale was maybe not quite as prolific for them as they had hoped, so when they wanted a new Quatermass film he was not able to deliver one quite yet.
Therefore Hammer turned to one of their staff, budding screenwriter Jimmy Sangster, to pen a script for a sequel, but Kneale was protective of his character and refused to allow permission. Their solution? Change the name of the lead scientist, here played by American import (for more international appeal) Dean Jagger, and go ahead with the production anyway, and the results were another hit for the studio, not to mention a new career for Sangster who became one of the most respected chiller screenwriters around. But X the Unknown was never truly going to rival Quatermass, and now is regarded as a footnote.
Which is kind of a shame, because if it was not up to Kneale standards it was nevertheless efficiently assembled and offered some fair suspense, along with some envelope-pushing gore, nothing that looks too ghastly by today's standards, but it's still surprising to see characters getting their flesh melted off in a movie of this vintage. For the first half of a pretty short effort, we have little idea of what has emerged from the ground to terrorise the locals, and the implication is that it may well be invisible, but those victims are reacting to something off-camera, so you'll be wondering what it could possibly be. It had to be said that the film was ruthless in bumping off those who crossed the monster's path.
So not only do the comic relief soldiers get melted - one of them played by a pre-singing fame Anthony Newley - but a little kid gets offed as well, which is particularly grim but illustrates the take no prisoners attitude of the menace. As to what that menace is, if you thought the first killer blob movie was, well, The Blob in 1958, then here was its predecessor, getting in there first with an extremely simple but undeniably effective movie monster, for it's a great big mass of radioactive mud which is bubbling up from the earth to devour the humans. Along with that effective item of nastiness on a budget, you got some Scottish colour to add personality to what might have been rather undistinguished otherwise, including one of the scuzziest drunks in fifties cinema, and as a bonus Leo McKern showed up as an inspector assisting Jagger's no-nonsense boffin for a serviceable middle-aged blob-fighting duo. If it remained in the shadow of Kneale, and still does, X the Unknown did entertain. Music by James Bernard, himself starting a great career with Hammer.