FIRST it was bent coppers in Line of Duty, then dodgy submariners in Vigil. Now the makers of both thrillers are back to plant a flag in your Sunday night with Showtrial (BBC1, Sunday), a tale featuring more coppers, plus lawyers, plus obnoxious posh folk, but so far no ocean-going, potentially planet-destroying vessels. Give it time.

We knew Showtrial shared producers with LoD and Vigil because the pre-publicity banged on about it ceaselessly. The tactic worked with Vigil in that the series started with a big audience and ended with a huge one as more viewers got on board with its strange blend of murder, politics and romance. Can the same formula work again?

The first episode certainly tried hard. There was a blizzard of datelines, “two days after student ball”, “day three of the investigation”, to give the tale of a missing woman some oomph. Meanwhile, a coachload of characters were introduced, chief among them Talitha Campbell, arrested on suspicion of sending threatening texts to the victim.

Talitha (Celine Buckens) was rich, arrogant, and deeply unpleasant to everyone she met, including DI Paula Cassidy (nicknamed “Butch” by a Crown Prosecution Service wag). Paula was a salt of the earth, working class lass, as was the missing Hannah. So the class war lines were drawn with a heavy marker. But was Talitha really as awful as she seemed?

A lot of strong women characters in the cast, as in LoD and Vigil, was meant to give Showtrial some feminist cred. Yet fundamentally it was still a drama built around foul deeds being done to a young woman. Another one. We did not see the victim’s body on a slab, true, but we saw the wheelie-bin in which she had been stashed like so much rubbish. The jury is out on this one for now.

Dalgliesh (Channel 5, Thursday-Friday) had a similar whiff of been there, done that about it. Hard not to, given the popularity of PD James’s novels and two previous series, one with Martin Shaw playing the poet/chief inspector, the other Roy Marsden. This time it was the turn of Bertie Carvel (Doctor Foster).

Carvel tried hard, but his Dalgliesh was just another in a long line of troubled detectives with sad back-stories. Though he did have a cracking pair of sideburns. Indeed, the best thing throughout was the 1970s vibe, with Jeremy Irvine coming close to stealing the show as Dalgliesh’s sexist, racist sidekick.

There were some cracking surprises in the finale of Guilt (BBC Scotland/BBC2, Tuesday/Thursday) as Neil Forsyth tied up the various strands of his story. I almost wanted to watch it again immediately but resisted for fear it may not have been as perfect as I thought (Lord, how Scottish is that?). Everyone got what they deserved, sort of, justice was done, kinda, and honour satisfied, on the whole. For a story that was meant to be all about revenge there was a lot of redemption and balancing of the moral books going on.

Now that he has proven there is no such thing as a difficult second album, one wonders if Forsyth will go for a third series. There are only eight episodes of Guilt in total; if this was a Netflix production, it would just be getting started. But how in keeping with this drama’s epic coolness would it be to simply stop here?

Plaudits all round, but especially to Bonnar for making a snake like Max so appealing; to Stuart Bowman for reinventing the role of gangster; to Phyllis Logan’s Maggie for being the toughest cookie of them all; and to Greg McHugh for showing us another one of his thousand faces, and a damn scary one at that. Mostly, kudos to Forsyth for showing that Scottish drama, every now and then, really is world class.

Here in Glasgow, for now the world’s capital of wanging on about environmental Armageddon (and rats, don’t forget the rats), the citizenry could do with the type of distracting fluff showcased in The Pet Show (STV, Sunday). Presented by Joanna Page (Stacey in Gavin & Stacey) it is an hour of light items that makes This Morning look like Channel 4’s Unreported World.

There was plenty to enjoy/sneer at, depending on your view of animal adoration.

Even those of us who long ago gave our hearts to some dog to tear came close to a sentimentality overload at times.

Then came the tale of Jess, a Border Collie working for mountain rescue who had gone out in a wild, wind-lashed night in search of an elderly dad reported missing by his son. Jess found Stan 20 feet down a ravine, thereby saving his life, and she did so for no more thanks than a pat on the head and (I trust) a few treats.

“We don’t deserve dogs, do we?” said guest Ben Miller, who was on the show to with his Black Russian Terrier, Jet. No argument here.