John Mills is impressively good at the start of An Endangered Species. Quatermass awakes in the bowels of Wembley Stadium to find that everybody has been taken (some seventy thousand people in the stadium itself, as well as Annie). As before, all that remains of them is an ashy substance. He staggers out into the daylight and is met by a group of guards, led by Brian Croucher.

This gives us an interesting contrast between two totally different styles of acting. Croucher is emotive, whilst Mills is steadfast and self-contained. John Mills, of course, had enjoyed plenty of practice in keeping a stiff upper lip in countless British war films – and that rather comes to the fore here. But I think he made the right acting choice. When faced with such a tragedy, the temptation is (like Croucher) to go overboard, but Mills was wise (and experienced) enough to know that less is more.

As we approach the end of the serial, it’s probably time to look at some of the themes contained within and ponder what Kneale was attempting to say. As he got older, Nigel Kneale gained the reputation of a grumpy old man and it’s fair to say that Quatermass reflects this.

It’s probable to assume that he spent the 1960’s not entirely in tune with the love and peace attitude of the flower power generation. All of the world’s ills (as seen in this serial) are laid at the feet of the young – this is explicitly stated by the older characters. The young (as depicted by the Planet People) are shown to be largely mindless sheep. This wasn’t the first time that Kneale had played on this theme (for example, the last episode of Quatermass and the Pit sees the majority of London under the thrall of the Martian influence).

But it’s more pronounced here and there’s no doubt that Kneale relished the idea of the older generation saving the day. “The theme I was trying to get to was the old redressing the balance with the young, saving the young.  Which I thought a nice, paradoxical, ironic idea after the youth-oriented 60s.”

Whatever the aliens are looking for, it seems to be contained within the young (although this doesn’t explain why Annie was taken from Wembley) and this means the older generation are largely immune. This leads to the incongruous sight of a group of white-haired scientists and soldiers toiling away to find a solution to the problem.

So we have a fairly clear picture that young = bad and old = good. There’s also the familiar theme that science = good and superstition/religion = bad. The conflict between science and religion is highlighted when Kickalong and his followers find Kapp alone in his observatory. Kapp still clings to the idea that he can contact the alien and transmit some sort of message.  After destroying all of his equipment, Kickalong offers Kapp the chance to join them. It seems that for a moment he’ll agree – but he manages at the last moment to resist.

Kickalong’s motivations have sometimes been difficult to understand and that’s the case in the following scene. We’ve already seen that he’s trigger happy, but he makes no attempt to kill Kapp – instead he leads his followers away. But he does kill one of them, Sal (Toyah Willcox), when she tells him that she wants to stay with Kapp. And it’s a brutal murder – he machine-guns her in the back.

After largely sitting out the third episode, Simon MacCorkindale has more to do in the final episode. And it’s he and Quatermass who man the invention that will stop the alien in its tracks. Quatermass has deduced that it somehow picks up a certain scent when a large group of young people are gathered together.  So (along with his octogenarian colleagues) he designs a device that will produce a scent which gives the impression that a million people are gathered together. And once the alien arrives, a small nuclear device should be enough to stop it. Of course, anybody in the immediate area will also die.

Those wondering if the plot-thread about Quatermass’ grand-daughter would be resolved will find that answered right at the end. She’s one of the Planet People (led by Kickalong) who descend on Quatermass and Kapp, just as they’re about to hit the trigger. There then follows a slow-motion sequence as the Professor and his grand-daughter are reunited and together they press the button which destroys them and the alien. Mills does his best here, but it is a slightly iffy scene – and the tinkling piano soundtrack doesn’t help.

The crisis is over. And with the destruction of the alien, somehow the whole world manages to right itself. This does imply that not only did the alien have the power to take millions of people from the surface of the Earth, it was also able to directly or indirectly influence every living creature. That’s something of a stretch – and the happy ending, after such a bleak, nihilistic tale, is a little jarring.

So where does Quatermass sit amongst Kneale’s works? At the time it received a generally lukewarm reception, with the Daily Telegraph calling the Professor “unheroic and unresourceful” whilst the Times found the production to be “so-so”. Kneale himself was later to register dissatisfaction with virtually every aspect of the production, from his own script to the performances of the main cast (including Mills and MacCorkindale).

Although it was Euston Films’ most expensive production to date (costing £1.25 million) it does look a little cheap in places (particularly the model-filming). Producer Ted Childs would highlight budget problems as well as the down-beat script as the serial’s main drawbacks. “The primary problems with it were (a) it was perhaps too depressing a story for a popular television audience and (b) the punters were used to a fairly high standard of technical presentation from American television… And we just couldn’t afford that.”

The fact that it remained rather unloved for many years is possibly the reason why it’s had a small upswing in popularity recently – as some people seem keen to champion it as an unheralded classic. It’s no classic, but it’s certainly worth a watch. Mills is unshowy but solid as Quatermass and MacCorkindale is more than decent.

But it’s probably true to say that if it hadn’t been a Quatermass story then it wouldn’t enjoy the reasonable profile it currently has.  Indeed, if Kneale hadn’t written it then it may have been largely forgotten today. However, it’s an efficiently made post-apocalyptic yarn that would have looked quite impressive in the late 1970’s (when the majority of British drama was still shot as a VT/Film mix).

The three Quatermass serials from the 1950’s do cast incredibly long shadows and therefore any fourth installment would have had a very hard job in equaling or surpassing their reputations. But if you ignore what came before, then Quatermass is well worth your time. Hopefully in the future it will receive the release it deserves (a BD containing both the four-part serial and The Quatermass Conclusion movie edit would be more than welcome).