Quatermass 2 (1957)

Brian Donlevy sort of grows into his part as the acclaimed scientist "Quatermass" in this quite menacingly put together sequel. He and his colleagues have been developing a plan to put a colony on the moon but when he encounters a man who is very, very, sick and then discovers a supposedly government run facility that is prone to meteor strikes, he begins to smell a rat. That's not all he smells as the place seems to be processing ammonia - but why would a food processing plant need that? Moreover, those exposed to this substance soon appear to assume zombie-like qualities that arouses his suspicions still further. Now allied with his police friend "Lomax" (John Longden), wily journalist "Jimmy" (Sidney James) and his no-nonsense assistant "Sheila" (Vera Day) they attempt to get to the bottom of this heavily militarised secret. This packs quite a lot into not even ninety minutes, and both the pacing and the writing help Donlevy to keep the story moving along rapidly without (thankfully) much reliance on the type of third-rate special effects we've become used to with low budget British sci-fi thrillers. There's also a little more of scientfic substance to an imaginative plot that also illustrates just how post-war British communities were coming to terms with their new society and proves how ineffective government oversight really was when official-looking military projects (our's or anyone else's) are protected by armed guards, barbed wire fences and conspiracy. It's a different sort of film from the "Quatermass Experiment" (1955) and it's really only the character himself who provides any sense of continuity; but it's well worth a look if you want something creepily plausible.