Comment: One of the most talked-about TV dramas at the moment is Sky Atlantic's psychological thriller The Undoing.
It's the fiendishly gripping tale of a wealthy New York couple whose gilded life is rocked when the wife learns that her husband has not only cheated on her (the swine!) but is prime suspect for the bloody murder of his illicit lover (the brute!).
Much of the feverish fan discourse is about the show's scene-stealing star. I am not referring to its A-list leading pair, Nicole Kidman and Hugh Grant. Nor even its impressive international supporting cast, which includes Canada's Donald Sutherland, England's Douglas Hodge, Venezuela's Édgar Ramírez and Denmark's Sofie Gråbøl.
No, The Undoing's breakout star is Kidman's green coat.
It's a long, hooded, bohemian number in moss green velvet. As Kidman's character, high-flying psychotherapist Grace Fraser, swishes around the Upper East Side wearing it, her flame-red curls flowing and a troubled furrow on those porcelain features, she resembles a chic sprite or the Scottish Widow after a makeover.
"Green coat" appears high up Google searches for the show. Two US fashion labels are already selling copies. Frankly, the outerwear is almost as watchable as the story itself.
The Undoing is just the latest entry in a burgeoning TV trend: the designer supersoap.
These glossy series are essentially pulpy potboilers but, with the addition of starry names and on-trend trimmings, they become elevated into something more aspirational.
This is low culture masquerading as high art – and viewers can't seem to get enough. Kidman is currently the undisputed queen of the genre. Her previous small-screen outing was in school gates mystery Big Little Lies – like The Undoing, made by US prestige powerhouse HBO.
Next year comes Nine Perfect Strangers, in which Kidman plays an enigmatic woman who runs a luxury wellness retreat. Expect sinister events between the spa treatments and macrobiotic brunches.
All three series – Big Little Lies, The Undoing, Nine Perfect Strangers – are written by prolific screenwriter David E Kelley, a former attorney who made his name with legal series Ally McBeal.
If Kidman is the genre's queen, then Kelley is its king. Together the two have cornered the market in snapping up the rights to zeitgeisty book-club thrillers from female authors and turning them into must-see miniseries.
(Big Little Lies and Nine Perfect Strangers are both based on novels by Australian author Liane Moriarty, while The Undoing is adapted from You Should Have Known by New York writer Jean Hanff Korelitz, wife of Irish poet Paul Muldoon.)
The crown princess to Kidman and Kelley? That's undoubtedly Reese Witherspoon, who starred in and executive-produced Big Little Lies alongside Kidman. Witherspoon has since gone on to head up breakfast news bitch-fest The Morning Show and Emmy-winning motherhood drama Little Fires Everywhere.
What do all these series have in common? Well, they're female-led and family-focused, with grabby premises that hook viewers – betrayal or murder, sex or scandal, a dark secret or a deadly rivalry.
Perhaps most crucially, they have the reassuring sheen of quality: big budgets, big names and the feel of a weighty box set, even if their storylines don't always deliver.
They've become catnip for midlifers who want some stylishly made but ultimately unchallenging binge-viewing at the end of a working day. They might purport to be profound – and occasionally achieve it – but they're essentially the screen equivalent of a page-turning beach read.
And don't underestimate the importance of these shows' glossy interiors. Set the action in glassy houses with enviable kitchens and statement wallpaper. Have the impeccably coiffed characters drink wine from vast, vaselike glasses.
Watch the upmarket audience flock in, safe in the knowledge they're watching something that fits their own brand values. Big Little Lies was set among the moneyed yummy mummies of Monterey, California.
So lusted-after were the show's beachfront mansions, with fire pits and infinity pools on expansive decks, they spawned articles in both Vogue and Architectural Digest.
Ditto The Undoing, essentially an East Coast equivalent in five-storey Manhattan town houses with mulberry walls, marble work surfaces and artfully distressed bare brickwork.
That coat isn't the only covetable item in its heroine's walk-in wardrobe, either. Kidman's burgundy wrap coat, embroidered cape and metallic Givenchy gown have also got fashionistas hot under the shearling collar.
Here in the UK, the closest equivalent was BBC marriage melodrama Doctor Foster, starring Suranne Jones, Bertie Carvel and a pre-Killing Eve Jodie Comer as the three corners of a tempestuous Home Counties love triangle.
The Fosters' showdowns unfolded in what was enviously dubbed their "power kitchen". When the cheating husband moved out, it wasn't to a bachelor flat but a minimalistic, Bauhaus-style $11.5 million mansion.
Slick, steamy Doctor Foster's big ratings and Bafta wins have since spawned a raft of home-grown imitators, mainly disappointing ITV melodramas – the likes of Liar and The Sister. Most had the scenic locations and designer hose taps, sure, but forgot the more important elements such as character and story.
Doctor Foster might have been lurid but it had high-end credentials. It was created by Olivier Award-winning playwright Mike Bartlett, who admitted it was inspired by the ancient myth of Medea. Doctor Foster's trappings might have been coolly contemporary, but the plot was 2,500 years old.
Its opening episode ended with a quotation from William Congreve's The Mourning Bride ("Heav'n has no rage like love to hatred turn'd / Nor hell a fury like a woman scorn'd") – a mere whippersnapper at three centuries old.
You see, trash works best when it's high-end trash. The finest examples boast a heady blend of plush production values, pop psychology, Grand Guignol twists and liberally sprinkled literary allusions.
HBO's critically adored, award-garlanded Succession – in which a Murdoch-alike media mogul's children fight to become his heir – is essentially Dallas or Dynasty with a superior script, baroque swearing and the overwrought air of a Shakespearean tragedy.
And what is The Crown, the fourth series of which arrives today, if not a blue-blooded soap opera? Peter Morgan's stately Netflix saga has a small cast of characters who we see develop over decades, with the occasional new arrival thrown in to shake things up.
It's essentially EastEnders or Coronation Street, relocated to a stately home and given elocution lessons. I jest, of course, although only partly. High-end TV trash is here to stay.
Us viewers are increasingly beholden to it. Now let's get back to lusting after Suranne Jones's kitchen island and Nicole Kidman's coat.