Smother: This is what an Agatha Christie-themed Glenroe looks like

Smother, RTÉ's new psychological thriller written by former Mr Selfridge show-runner Kate O'Riordan, is a long way from perfect. There are too many characters, several of whom feel blandly interchangeable (have a bow stubbled middle-aged blokes #1 2, 3).

The plot unspools like fresh-from-the-microwave Midsomer Murders. And it doesn't take advantage of the Co Clare setting by evoking, as shows such has Broadchurch do, a specific sense of place. In Ireland there is no psychosphere.

But it possesses a pulse and it clicks together effectively as a Sunday-night whodunnit – more than can be said for lamentable recent RTÉ excursions such as The South Westerlies. It's competently watchable, and you won't cringe through the opening episode (RTÉ One, 9.30pm). Nor will you have slipped into a disinterested stupor by second ad break. That counts as progress.

Dervla Kirwan and Seána Kerslake are the two big names. The former plays Val Ahern, a wife and mother who has had enough of her slimy, philandering husband Denis (Stuart Graham) and has decided to move in instead with her younger lover. Her boyfriend is played by Thomas Levin, a Danish actor in two minds about whether or not to attempt an Irish accent.

A lot of the time we are not all in this together

---

Frasier reboot: The pompous, insufferable, lovable snob returns after 17 years

---

Pat Kenny is fuming – and it’s not because of his property dispute

---

He is introduced, along with the rest of the cast, during a birthday party for Val that goes on longer than the wedding at the start of The Godfather. This is also where we meet Kerslake as Grace, youngest daughter of Val and Denis. Her older sisters – portrayed by Niamh Walsh and Gemma-Leah Devereux – are half-siblings who formed a blended family when their parents married.

Grace has deep-seated psychological issues. And it isn't beyond the bounds that she is the one responsible for the death of her father. What we do know is that whoever killed Denis clearly had a head for heights. Smother begins with the dastardly dad attacked by a mysterious assailant during a clifftop ramble near the family home in Lahinch the morning after the Neverending Party. He plunges to his doom, and the opening credits roll.

Did Grace attack him? Or was it Val? Or perhaps one of his other daughters? Denis had hidden financial woes and was planning to sell off both Grace’s cafe and the family mansion. When push came to shove, is that why he was jostled to an untimely demise?

Smother is more end-of-weekend comfort food than prestige TV. And the cast, who were required to socially distance for the shoot, are to be credited for buying into the Cluedo-ness of it all. The exception is the usually solid Kerslake, who appears to be starring in a more unhinged melodrama and whose amped performance co-exists uneasily alongside that of the more restrained Kirwan.

The series ultimately exists to answer the question: what would an Agatha Christie-themed Glenroe have looked like? It certainly suffers from an excess of fuddiness. Val and Denis, for instance, are nominally Gen Xers but, in demeanour, dialogue and dress sense, have beamed in straight from the 1950s.

Still, Smother hangs together to the point where it’s possible to ignore the sometimes lumpy exposition (“you’re sober now and that’s the main thing”). It is pretty good (you are genuinely interested in seeing the mystery of Denis’s death unpicked). And for Irish small screen drama pretty good is, sad to say, better than expected.