LOCK the doors, stop the clocks, put the phone on silent and get your snacks sorted. On Sunday night we’re down Hebden way for the last time - and life will never be the same again.

How can it be the finale of Happy Valley already? The. Last. Episode. Ever. I’m getting a stress rash wondering how I’ll cope without it.

Unless you’re one of those weird people who doesn’t have a telly, or you’ve been watching the other side for the past five weeks - Vera? Really? - you will, like me, be so immersed in the chilling underbelly of the Calder Valley that, with four days to go until the last ever episode, you can think of little else.

Will Tommy and Ryan make it to the Costa for that bungee jump in the sun? Or will there instead be a betrayal, a set-up and a stand-off at Baitings...?

Will Joyce hand over that retirement whip-round, including the spare change, to Sgt Cawood? Will Darius Knezevic keep his hands clean (we already know the man has anti-bac wipes in his designer suit pockets) and head off to Bradford for a political career? I mean, there’s a spin-off series right there.

And what of Faisal? Has he got away with murder? Will Clare fall back into old ways? Is Neil all he seems? Will Ann cut the mustard in CID? Will little Poppy take off her coat? And will Todmorden ever have its own alien liaison officer?

Sally Wainwright’s hugely popular drama has kept us gripped since it returned for its third and final series on New Year’s Day. It has pulled in around 10 million viewers, with the second episode beating Prince Harry’s ITV interview in the ratings.

And come 9pm on Sunday, an estimated eight million of us will be glued to the final episode. With Tommy Lee Royce - murderer, serial rapist, kidnapper, drugs offender and all-round sinister smiling psychopath - gunning for his nemesis, Sergeant Catherine Cawood, we’re in for the mother of all showdowns.

In an on-demand age, when we can binge watch an entire box set in one greedy sitting, it has been a breath of fresh air to have a TV series released weekly. It’s proper water-cooler telly, even for those who don’t actually gather round an office water-cooler, and because none of know what’s going to happen - several different endings are said to have been filmed - there are no pesky spoilers.

It is that rare thing these days - a show that families watch together. My nephew rarely emerges from his bedroom, or the gym, most evenings, but on Sundays he’s on the sofa with his mum for Happy Valley . My friend says her two daughters ring her to discuss each episode. This is Gen Z, that doesn’t watch TV, yet is totally invested in an old-school weekly series about a jaded smalltown cop, a middle-aged woman who must seem ancient to anyone under 25.

Creator Sally Wainwright must of course take credit for this. Happy Valley is bleak but beautifully written; subtle nuances and deadpan humour woven into the rhythms of northern speech. The cast, headed by mighty talent Sarah Lancashire, is excellent, and the Calderdale/West Yorks backdrop is the icing on the cake. All of this makes it great, must-see TV. Having to wait a whole week to watch each episode is even more exciting.

We have endless channels, we record, catch up and stream in the blink of an eye. We watch stuff anytime, anywhere, on laptops, phones, consoles. Yet there remains something primal about the shared experience of watching the same thing at the same time on TV. In 1953 more than 82 million viewers watched the Queen’s Coronation on television sets. TV has united us ever since - the Moon landing, pubs and churches closing early for the Forsyte Saga, Morecambe and Wise at Christmas, Who Shot JR? Charles and Di’s wedding, Live Aid, Dirty Den and his divorce papers, “Final answer” from Judith Keppel, world cup finals, Line of Duty. And, this Sunday, Catherine Cawood meeting her fate - hopefully heading for the Himalayas in her old Land Rover.