When watching a murder mystery is it wrong to be paying as much attention to a character’s fringe or kitchen as the plot? Asking for a friend (okay, busted) who found her gaze fluttering everywhere during Magpie Murders (BBC1, Saturday).

It is not that Anthony Horowitz, adapting his novel, has failed to supply a gripping enough yarn. Indeed, he has turned in two of them, one set in the present and one in the past, that play out side by side.

In the mitts of another writer this might be too much work for a Saturday night, but Horowitz has a Christie-like way of cutting through the clutter to focus on what matters, which in this case does include a fringe and a groovy kitchen. Both figure in the life of the central character, book editor Susan Ryland, as played by Lesley Manville. Some of us aspire to be like Susan/Lesley when we grow up.

The tale begins with bestselling whodunnit author Alan Conway (Conleth Hill) sending off his latest novel to his publishers.

But wait, the final chapter is missing. Conway cannot help because he has been found dead in circumstances that mirror the fate of a character in his novel. There’s nothing else for it: Susan must leave her kitchen and boyfriend behind and pop down to Conway’s home to sort things out.

Magpie was a word-of-mouth hit on BritBox, and its reward is a prime BBC1 slot just after the ever-cheery (not) Casualty. The full series is on iPlayer if you must binge.

Unforgotten (STV, Monday) ended its current run on a high. As the first series without Cassie this was always going to be a tricky one for its writer, Chris Lang, but he paced it just right.

New DCI Jess James (Sinead Keenan) could have been straight with Sunny (Sanjeev Bhaskar) from the start about her bin fire of a home life but it was more convincing, and typically Unforgotten, to let the story out reluctantly, bit by bit, as a person would.

Sunny reciprocated in kind, though it pained him to do so

With the personal stuff rationed the investigation took centre stage. The story deserved it, being a tangled tale that ran from the top of society to the bottom and managed to get some political points across along the way.

A messy sort of justice was dispensed in the end. It suited the tale as much as Jess – finally addressed as Jessie by Sunny – does this show.

So to Rain Dogs (BBC1, Tuesday), a comedy-drama so bleak it should come with a prescription for anti-depressants. As with many an HBO production, this one set in London, it arrived here trailing plaudits.

Daisy May Cooper (This Country) plays Costello, alcoholic, stripper, aspiring writer, and mother to a ten-year-old daughter, Iris. Also in the pair’s life is posh ex-prisoner Florian Selby (Jack Farthing), though it is not immediately clear how he fits in.

Opening with the eviction of Costello and Iris from their flat, writer Cash Carraway was only just getting started with the grimness. Seat at a Soho peep show anyone?

Though disturbing in places, and sometimes just plain nauseating, Rain Dogs has a lot going for it, much of it coming from Cooper. You want to see how life turns out for her character, which is as good a reason as any to try another episode.

Reunion Hotel (BBC2, Thursday) was a bizarre piece of television presented by Alex Jones, her off the One Show. It is as if someone had said, “I like Long Lost Family and I like makeovers for a good cause, and everybody loves happy endings. Why don’t we whiz them all together and set the whole thing in a Welsh hotel?”

There was serious business happening, including someone meeting his adopted brother for the first time, but then we would cut to cheery hotel staff behaving as though they had wandered in from a reality show.

Meanwhile, Jones bustled about, moving people in and out of rooms like a Welsh Sybil Fawlty.

While one couldn’t fail to be moved by the stories, an hour was too long, the hot and cold running faffing was annoying, and the tone was all over the joint. Nice hotel, though. Wonder if the owners have ever been on Four in a Bed.

How are sir or madam enjoying Succession (Sky Atlantic, Monday)? Fittingly enough, the final series has an end of days, anything could happen, vibe about it. With the plot just more of the same, it’s the zingers and the performances that keep us coming back.

This week’s winner of the wholly unofficial, and no prize offered, Succession Line of The Week competition goes to Cousin Greg. Describing how Logan is moving among the staff at his news channel, Greg tells Tom: “It’s like Jaws, if everyone in Jaws worked for Jaws.”