*Spoilers for Game Of Thrones season 1-3*
Five years ago, on a quiet night in early summer, households the world over recoiled in horror as hit fantasy show Game of Thrones played perhaps its most infamous trump card yet. The Red Wedding.
In episode nine of the third season, fan favourite Robb Stark travels to the castle of fickle allies House Frey for an unassuming wedding; his uncle Edmure being betrothed to one of the vulgar Lord Frey's daughters.
But after the ceremony, during the feast, things take a violent and traumatic turn.
Robb, his mother, and all of their attendant supporters are betrayed by the Freys and the slippery Roose Bolton - and the entire occasion descends into a visceral bloodbath of slaughter.
By the time the dust settles, Robb, Catelyn, and hundreds of Stark soldiers lie dead. The former coldly dispatched with blades to the heart and throat.
Even for a show that had acquired a reputation for violence and shock-factor, this was a moment that left viewers around the world in total shock.
A 'fantastic', terrible twist
From Roose Bolton's sly nod down to his chainmail-clad arm, to Catelyn Stark's chilling, final wail of despair (Michelle Fairley's performance is heart-wrenching), the sense of escalation is extraordinary.
"I remember, as the scene unfolded, thinking variations of 'Oh s***!'," says Chris Slinn, via our Screen Babble discussion group.
"I don't think it was a game changer, because we've seen TV shocks in the past. I don't even think it changed my opinion of the show that much, given Ned's demise so early on.
"But it was a fantastic story twist though - as someone who had not read the books."
Those familiar with the source novels by author George R R Martin knew what was coming, of course. But even they were taken aback by the TV version.
Martin has often used the Song Of Ice And Fire book series to subvert heroic fantasy tropes. And this may perhaps be his crowning example.
Yet certain changes in the adaptation actually served to make the TV version even more harrowing.
We, and poor Arya (who was so close to reuniting with her family), see Robb's wolf Greywind murdered in his pen by laughing Freys, who pepper the defenceless animal with crossbow bolts.
In the book, Robb's wife Jeyne is not with child, and is not present for the massacre. In the show, however, his wife Talisa is all too present and all too pregnant - and we flinch as a Frey man brutally stabs her again and again in the belly.
The TV show also spent a much greater amount of time getting the audience to invest in and care for Robb. In the books, he is not even a point of view character. In the show, he all but becomes the 'hero' of the saga in seasons two and three.
But much like his father Ned, he learns all too late that being the hero is no protection in this ruthless universe.
"Having already read the books, I knew what I was getting into," comments Khalil A. Cassimall. "But still my jaw dropped.
"The most amazing thing about the scene is how they succeeded in building the dread." Something Cassimall notes author George RR Martin also did "magnificently" in the book chapter.
'I never saw it coming'
Should viewers have known what to expect?
After all, Ned's own death in the penultimate episode of season one had been a statement of intent. A warning sign that normal conventions and 'plot armour' did not apply.
We also got ample warning that the Freys and Boltons were not to be trusted; David Bradley and Michael McElhatton doing such a great job of playing shifty villains-in-waiting. This being very much a show that deals with consequence, Robb's breaking of his own marriage pact with the Freys, and execution of Lord Karstark, was always going to come back to haunt him.
But still, fans were taken by surprise. As evidenced by the sheer avalanche of aghast YouTube reaction videos in the wake of the event.
"I had no idea it was coming," says Karen Dunn, simply.
Ultimately, The Red Wedding may not have been Game Of Thrones' first big gut-punch twist. But it has arguably been its most effective and enduring, inspiring countless memes, debates and even a song for Coldplay's spoof Game of Thrones musical.
Five years on, it's hard not to look back at the episode in question without recalling its nerve-jangling build-up, gradual horrifying realisation, and sickening climax.
As TV scenes go, it's undoubtedly one of the most intense and memorable in small screen history.