The opening scene of The Fourth Horseman makes it quite clear that Abby Grant (Carolyn Seymour) has led a privileged life.  Not only does she live in a large house, but there’s also a tennis court (complete with an automatic serving machine).  And when she enters the house, Abby thinks nothing of asking her housekeeper Mrs Transon (Margaret Anderson) for a cold drink – the notion of fetching it for herself would presumably never have crossed her mind.

Jenny Richards (Lucy Fleming) on the other hand, seems to live in much more modest surroundings – if we assume she shares a flat with her sick friend Patricia (Elisabeth Sinclair).

What is established early on is that the two women (although they’ve yet to meet) have very different outlooks and attitudes.  Abby has a strong and independent personality whilst Jenny seems to rely much more on other people.  After the virus has burnt itself out, we’ll see how this works in the context of the series.

The increasing seriousness of the virus epidemic is drip-fed through the opening part of the episode in various ways – Abby listens to a radio report in her car which discusses how the crisis is being dealt with in other countries, Jenny visits the hospital to get help for her friend and is told that there’s nothing to be done, etc.

Other signs that the delicate infrastructure of society is slowly breaking down are also threaded through the opening twenty minutes or so, such as problems with the telephone and radio and reports of long delays on the trains.  Although issues with all three in mid seventies Britain was not exactly unusual!

The question of information, or mis-information, is dealt with.  Up until now, nobody has really taken the epidemic seriously (mainly because the news reports have greatly downplayed its effects).  In the pre-internet age, the flow of information would have been greatly restricted, so this is quite credible.  Abby and her husband David (Peter Bowles) therefore begin to slowly understand that it may take more than “a few days” (as David originally believes) to put things right.

The symptoms of the illness (sweating, pains under the arms) are quickly established (Patricia and Mrs Transon both exhibit them).  Abby is also later infected, whilst David seems to be quite healthy – so it’s reasonable to assume that Abby will die whilst David will live.

Of course, the reverse happens – Abby awakes after six days or so from the fever to find that she’s one of the few to have had the illness but not died and then discovers her husband’s dead body.  She walks through the village and doesn’t find another person alive.  “Oh god, please don’t let me be the only one.”

At the end of the episode she enters the bedroom and cuts off her long hair.  The unspoken inference is that she knows her old life is over, so now she has to start a new one (beginning by locating her son, Peter).  Symbolically, cutting her hair could be said to be part of this.

Earlier, Abby discussed with David what would happen to a city “if it all breaks down, all at the same time. There’s no power, no lighting or cooking. And food, even if you get it into the city you can’t distribute it. And there’s water, sewage, bleugh. Things like that. You know it just never occurred to me when I lived in London. The city’s like a great big, pampered baby with thousands of people feeding it and cleaning it and making sure it’s alright.”

Dialogue like this, as well as the radio and train station announcements all help to quickly establish what the problem is and how it can and will accelerate.  Immediately after Abby describes how a city is essentially a living thing, we see Jenny urged by her doctor friend to get out of the city and into the relative safety of the country, which she does.

It’s clear though that her solo adventures are a great deal more uncomfortable than Abby’s.  Jenny (whilst a resourceful person in many ways) is possibly not someone who would be able to survive on her own, so it’s fortunate that she later meets Abby and Greg.  Before that though, she briefly runs into Tom Price (Talfryn Thomas).  From their one scene here, you wouldn’t necessarily guess that he’d reappear and become a key figure in a number of early episodes.  From this appearance it might be thought he’d be the series’ comic relief character, but we’ll see later that he also has his darker side …..

With only limited resources, it’s quite tricky to create a London that’s virtually empty of living people (but this is achieved by shooting at night and the night-time filming does also help to increase the sense of unease).  The Fourth Horsemen benefits from being shot in the normal way for BBC drama of this period – VT for the studio scenes and film for the location scenes.  The majority of the later episodes would be all VT, which does actually work quite well, but the film night shooting in this one is very evocative.

We’re told that the virus is a mutant strain and is quite unstoppable.  In a few days, the dead will outnumber the living and all the major cities will resemble cess-pits.  The question now must be, what will the survivors do next?

When Abby reaches her son’s school she finds that he’s no longer there – together with a party of other boys they left before the worst of the sickness.  Dr Bronson (Peter Copley) tells her that her son may already be dead, although Abby still clings to the hope that he’s still alive.

Dr Bronson also acts as the mouthpiece for Terry Nation as he describes what has to happen once the virus has done its work.  Abby doesn’t, at first, believe that the immediate problem is too serious, since there must be an enormous stockpile of food and machinery.

Dr Bronson tells her that “they’ll be enough for many, many years  but that would be simply scavenging, wouldn’t it? And a constantly diminishing supply. What is important is learning again. Things you’ve never even needed to consider before. For instance, could you make that candle? Where does the raw material come from, do you know? Could you make something as simple as a candle from scratch? A book will tell you how electricity is generated, but could you do it, right from the very beginning? Find the metal in the earth, dig it up, refine it, turn it into wire? Could you make and cast glass for a light-bulb? You’ll need to know every part of every process.”

This is one of the mission statements of the series.  Everything has to be learnt again, otherwise the human race will face total obliteration …..