It was enough to make Downton Abbey viewers choke on their Sunday evening boiled egg and soldiers in front of the fire. The usual cosy, escapist encounter with a fantasy historical world was shattered by an unpleasantly realistic rape, when lady's maid Anna was brutally assaulted by a visiting valet.
The cries of disgust and outrage were almost instantaneous: "sick and sensationalist", "cheap", "designed to shock", "a moment of tawdry tastelessness".
The fact that the rape was enacted, off-screen, to the sound of Dame Nellie Melba (aka Kiri Te Kanawa) singing a Puccini aria only enraged the Downton diehards still further, the soaring beauty of her voice bringing the unexpected ugliness of the latest plot twist into sharper contrast.
The Countess of Carnarvon, who owns Highclere Castle, where Downton is made, summed it all up when she remarked, with appropriate aristocratic diffidence, that she preferred "to look at nice things on a Sunday night".
Yah, we do, don't we? A bit of high-class murder, Miss Marple-style, is fine, as long as there's not too much blood – but most people don't wish to encounter something as harrowing as a violent rape. Especially when all they really wanted was a fairly gentle story about posh rich folk in the olden times.
Admittedly, ITV tried to soften the blow. It warned in advance that the episode would contain scenes that some people might find violent and upsetting.
Soon after the offending programme was broadcast, up popped Joanne Frogatt, who plays Anna, to defend both Downton and its creator, Julian Fellowes. She said: "I was really proud of the show for tackling a subject like this. It's a really brave thing to do and I really do believe that Julian's written that in a way that is not gratuitous at all ... He's done a beautiful job of hitting the right note with it."
Frogatt added that it was to Fellowes's credit that the camera cut away from the moment of the rape itself: "Julian, and this is a credit to him, was adamant that we wouldn't depict that kind of violence against a woman on the screen ... and that's an incredible thing in this industry in this day and age. And the shock value was there without having to depict anything graphic."
Oh, so that's all right, then. Instead of indulging in a grubby attempt to boost ratings for the fourth series of the period melodrama, Fellowes was, in fact, setting an example to other programme-makers about the most sensitive way to depict sexual assault. Which sounds about as plausible as one of Downton's own famously convoluted plots.
Handily enough, there was also a media-friendly academic (there always is) willing to back up the storyline on the grounds of historical accuracy.
Dr Pam Cox, who lectures in social history at Essex University, and presented a recent BBC series about domestic servitude, said that the situation was realistic. She pointed out that female servants were often raped, abused and harassed.
"There was a hierarchy within the servants' hall and butlers and valets were in a position of power," she said.
"As to whether a servant like Anna would have reported such an attack, it was extremely common not to. If we see women in the 1970s only coming forward now in the light of the Jimmy Savile inquiry, what does that mean for women decades earlier?"
But both Cox and Frogatt are missing the point.
Nobody looks to programmes like Downton for their educative value (let's be honest, if they did, they'd come up with a rather wonky idea of what actually went on in the early years of the last century).
We're not talking harsh social realism here, EastEnders in floppy hats, flapper dresses and shawls. The period accuracy in Downton has always come second to the fantastical twists and turns of the story and it's that unashamedly melodramatic quality that viewers enjoy.
Julian Fellowes is far from alone in turning to sexual violence for its useful shock value.
For instance, The Fall, the BBC crime series set in Belfast, and starring Gillian Anderson, has been described as an extended rape fantasy, due to its lingering scenes of violence against women.
Feminist writer Bidisha got it right when she asked: "What is it with male writers scribbling in a quick rape of a woman to spice things up? ... I'm not campaigning for rape survivors by day, watching it served up for entertainment at night."
Calling for greater responsibility in the portrayal of rape, Bidisha said that the Downton episode was "gratuitous, obscene ... it made me want to switch off."
But did she turn it off? In fact, did anyone?
Official figures show that an average of 9.2 million viewers watched the offending episode of Downton, yet in spite of the loud declarations of disgust, just a handful of people – around 60 – complained to ITV.
Perhaps the real scandal is just how inured we have become to the depiction of grotesque assaults on women – and all in the name of mainstream entertainment.