There aren't many TV series that can drive a song to the top of the charts across the Western world. There are very few that can rack up half a billion hours of collective viewing time in just a fortnight.

And it's not your average show that can push millions of people to step away from old-fashioned TV and sign up to new-fangled streaming services - as many of us found ourselves doing in 2016, to watch season one of Netflix's 'Stranger Things'. Our grandparents did a similar thing in 1953, when they bought tellies to watch the Queen's coronation.

We're now on season four of 'Stranger Things'. Every generation has a piece of portal fiction that captures its imagination. In this trope, heroic children stumble through some gateway into another dimension, which teaches us something profound about our own.

In Victorian England, at the height of Britain's "imperial century", Lewis Carroll's 'Alice's Adventures in Wonderland' enthralled a country captivated with orientalised stories of far-off lands, while mockery of an oppressive Queen of Hearts resonated.

In 1900s America, arguments about monetary policy and the desire to 'return home' to a previous era as modernity erupted were expressed through L. Frank Baum's 'The Wonderful Wizard of Oz', with the conflicting needs of industrialism, agrarianism and a failing military represented by the tin man, the scarecrow and the cowardly lion.

The blazing Christian allegories of C.S. Lewis's 'The Chronicles of Narnia' spread like forest fires during the 1950s religious revival, as people desperately sought meaning after the horrors of the Second World War.

Philip Pullman's 'His Dark Materials' trilogy echoed debates between religion and science as church-going collapsed during the 1990s.

These tropes - similar to underworld stories, but without the need to die; a little like time travel, but without the explicit past or future - go back to the dawn of storytelling. In Japanese culture, fantasy about portals to other dimensions is so prominent it has a name: Isekai.

In the Celtic folk tradition I was weaned on, there's a trope where the hero lost in the hills goes into a cave and finds themselves among the fairy folk, leading to various adventures. Perhaps, my parents used to say, these were memories of Celts arriving in Scotland, and coming across earlier human inhabitants.

'Stranger Things' is today's version of these myths. But unlike most, the 'other world' isn't quirky or enchanting or exciting in any way. It's just straight-up terrifying. The "Upside Down", as the protagonists call it, is a mirror of our world, but filled with monsters and horrors we could previously only imagine.

From the Cold War and Vietnam to Trump

This other world was first introduced to viewers in July 2016, as Trump rode the Republican primaries to the White House and just weeks after Britain voted to leave the EU: things that almost all in the age groups who watched it were deeply against.

The first children dragged into the Upside Down, Will Byers and Barb Holland, are both coded as LGBTIQ - we're explicitly told in the first episode that Will's dad thinks he's "queer" - an obvious nod to fears about who would be the first victims of this new Trumpian, post-Brexit order, as rising rates of transphobia and homophobia have proved.

As the seasons unfold, with tropes from 1980s horror films and Cold War conspiracy theories abounding, it soon becomes clear that the real enemy here isn't so much the monsters of the Upside Down, but sinister forces within the American state itself, which founded Hawkins Laboratories to experiment on children.

Unethical experiments on people, causing them serious harm and often death, are common in recent US history. But unlike the child victims in 'Stranger Things', most of whom are white, the true victims were almost always Black. Would a more realistic depiction, with Eleven and her fellow inmates played by Black actors, have been so popular? The ugly answer, I suspect, is no: white audiences are still too conditioned by white supremacy to see themselves in tortured Black people.

Real events - such as the US army's use of Agent Orange during the Vietnam war and the damage it did to its own soldiers and their subsequent children, and the satanic panic of the 1980s - are woven into the storyline of Stranger Things. Most importantly, the Cold War forms the background and context for the show. All this helps create a cultural mythology for a millennial and Gen Z audience about the time just before we can remember - another world that seems so different from our own, but yet feels pretty familiar.

'Alice in Wonderland', 'The Wizard of Oz', 'The Chronicles of Narnia' and 'His Dark Materials' all take place in roughly the periods in which they were written. 'Stranger Things' is often seen as a nostalgia-fest for the 1980s, but its writers, the twin Duffer Brothers, were born in 1984, a year after the story begins. Its audience is largely millennials or younger.

Like baby-boomers watching Second World War documentaries on loop in weak-kneed faux-nostalgia for an era they didn't actually live through, our enthusiasm for the years just before we can remember is telling.

Self-reported happiness in the UK peaked in 1976, and has been declining ever since. In real terms, wages in the US were very slightly higher in 1983 (when the show begins) than in 2016 (when it first aired) and have been essentially stagnant for 40 years.

The middle-class Wheelers, parents to heroes Mike and Nancy, probably found that their future wasn't as they hoped and most likely would have voted for Trump. Working-class Joyce Byers (mother of the missing Will), who would now be in her 80s, is probably as poor as she was then.

The future is female

Cultural theorist Fredric Jameson famously wrote that it's easier to imagine the end of the world than it is to imagine the end of capitalism. With climate change, species loss and rising fascism, it's easier for many younger people to imagine a scorched hellscape populated by cruel monsters than it is to imagine a parallel universe of equality and abundance. It's easier to get excited about what life was like before neoliberalism ripped through everything than it is to look forward to a better tomorrow.

If there's a hopeful message in the popularity of 'Stranger Things', it lies in its women. Joyce Byers and Nancy Wheeler (older sister of Mike, best friend to Barb) are probably the bravest characters. The superhero at the centre of everything is a teenage girl - Eleven. While early seasons can feel like a bit of a boys' own buddy show, the clear message is that it's women - screwed-over, oppressed women - who will save the world. And, as with Buffy, they'll do so not on their own, but in collectives.

Shows with such powerful female characters were rare, and rarely so popular, a generation ago. But perhaps younger men are more prepared than their dads were to follow stories about women and girls saving men and boys.

There is, of course, another reason why 'Stranger Things' is so popular. It's brilliantly scripted, beautifully crafted television. The next instalment is out tomorrow and I recommend a binge.

From openDemocracy