TO think it all began with a cheeky one-off Hogmanay special built around a steak pie. Now back for a fifth series, Two Doors Down (BBC2, Monday) has reached that sweet spot in a sitcom’s life when viewers know what to expect, and that’s just tickety-boo with them.

So Beth (Arabella Weir) was cooking, as she always is, husband Eric (Alex Norton) hovering. Their son Ian and his partner Gordon (Jamie Quinn, Kieran Hodgson) were coming round, like they generally do; and neighbours Cathy and Colin (Doon Mackichan and Jonathan Watson) and Christine (Elaine C Smith) had invited themselves to dinner, as per. Let the fun and games commence.

Gordon had already raised eyebrows with his vegetarianism and alcohol-free beer. But when it turned out he had never been in a fight the company was scandalised. “Has nobody ever, just, punched you?” asked an incredulous Cathy.

There followed a good old Glaswegian pile-on about Gordon’s failings, an exercise designed to crush the Englishman’s spirit but in a loving, one of us, yer at yer auntie’s, way. Colin gave him a safety alarm. Did we know it was going to be set off by accident? Yes. Did that make it even funnier? Of course it did. There is plenty of life in Simon Carlyle and Gregor Sharp’s creation yet.

You Don't Know Me (BBC1, Sunday-Monday) was a lucky bag of a drama, some surprises good, others less so. The story, a young man accused of murder, was strong, and the mostly black cast excellent, yet try as I might I could not buy in to how the tale was told.

It started with the main character, Hero (Samuel Adewunmi), in the dock. He had refused to give evidence in his defence but wanted to do a closing speech. Don’t introduce any new evidence, said the judge, reminding all present of a trial basic. And what did Hero do? Precisely that. Depending on your view this was either a clever dramatic device or a stretching of credibility too far.

Other hard to believe twists followed, each one pulling the viewer out of the drama just when it was becoming gripping. Two parts to go, you can only hope the end justifies the faff.

Dolly: The Sheep that Changed the World (BBC2, Wednesday) was a largely by the numbers documentary about a gobsmacker of a breakthrough: the first ever clone of an adult animal. It happened here, in Scotland, a place others (especially rich American pharmaceutical companies) thought too wee and too stupid to pull anything off.

But it was the humility of the staff at the Roslin Institute, backed by a solid core of expertise, that gave them an edge. Other labs might have had the megabucks, Roslin had the characters and the dreamers and a “let’s do the story right here attitude”.

This was the scientists’ story, told largely by themselves, and very charming it was at times. I loved the notion of one of them, having to keep an embryo warm during a walk between buildings, popping the container into her bra.

Keeping the tone chummy lifted what would otherwise be a dry story punctuated with endless shots of pipettes piercing cells. The attempts at levity did not always work, as when the objections of animal rights protesters were raised. At one point, we learned, a group had tried to liberate Dolly but they could not pick her out from the rest. “Sheepishly they left empty-handed,” said the clearly tickled narrator. Oh dear.

Otherwise, it was a deft study in science pushing the boundaries and the daftness of us mere mortals, press and public alike. One headline asked, “Can we raise the dead?”

Dolly was a star to the end. Roger Highfield, science editor of the Daily Telegraph and one of several excellent value talking heads, said she was a “bit of a diva”. A one-off you might say. The irony.

The Cult of Conspiracy: QAnon (Channel 4, Tuesday) found Scouse journalist Ben Zand talking to some of those who believe, among other things, that a cabal of rich and powerful paedophiles rules the world; that the 2020 election was stolen from Donald Trump because he was close to exposing their evil deeds.

To no-one’s surprise, they turned out to be a bunch of space cadets wired to their own personal moons. The sheer amount of stupidity on screen was exhausting. We did not find out anything new, but it was a timely reminder that stupid people can still be dangerous. Zand left us with the thought that some of these anti-politicians now want to run for office. What a time to be alive.

For security reasons there were no previews available for Sex and the City reboot, And Just Like That (Sky Comedy, Thursday), and it aired after the magazine had gone to bed. See the review online to find out if it was kept under wraps because it was a little gem …