Killers In Our Midst:Clean Sweep.

"These post-mortems. They know what you ate last. They weigh your heart and they weigh your brain. But really they don't have a clue what's going on deep down inside" - Jason Mohan

The Irish thriller Clean Sweep (BBC4/iPlayer, directed by Ronan Burke and Yves Christian Fournier, written and created by Gary Tieche) is tense, it's easy to watch, and it's sometimes thrilling. It's also - in many places - faintly ridiculous. It features ludicrous disguises and even more ridiculous fake beards and the actual killer (we learn who that is very early on) acts obviously guilty pretty much all the time. Which almost nobody picks up on.

I had to suspend belief on multiple occasions yet I still thoroughly enjoyed it. Set in a very picturesque looking Bray in County Wicklow, we begin with Shelly Mohan (Charlene McKenna) in her underwear, over a sink, drinking red wine and scrubbing something - presumably bloodstains - from her clothes. Shelley's a housewife, a mother of three, and she's living an averagely pleasant life. Suburban home, nice kitchen, nice dog, spagbol for dinner, and keeping her rubber gloves on for sex with her husband Jason (Barry Ward).

Which gives 'rubbering up' a whole new meaning. Jason's a detective in the Gardai and he's keen to get a promotion both for reasons of personal ambition and to help his family who are having minor financial struggles. He's not the most sympathetic character. He mocks Shelly's idea of returning to work and he appears to have been unfaithful to her more than once.

Both their worlds are changed when a stranger from Shelly's past successfully tracks her down. Charlie Lynch (Adam Fergus) sports an atrociously unconvincing false beard and his behaviour is, from the start, very suspicious. Shelly is clearly not pleased to see him but, nonetheless, agrees to meet him in a hotel room.

Which she does in a disguise (though not quite as daft as his disguise). Charlie brandishes a bible, he talks about redemption, salvation, and forgiveness and he tells Shelly that Jason is cheating on her with his colleague Fiona (Jeanne Nicole Ni Ainle) and he calls Shelly by another name:- Maggie. Shelly tells him that she's called Shelly and that "Maggie is dead" and it soon becomes clear that she's hidden a big part of her past.

Charlie threatens to expose her so she shoots him dead. That's not a spoiler. That all happens in the first ten minutes or so and the fact that Shelly was carrying a gun on the school run is an indicator that there's a lot more going on with her and much of the rest of Clean Sweep is made up of the Gardai's attempts to solve Charlie's murder and to find out what has happened in Shelly's past. What she's done? What's been done to her? Is she Shelly? Or is she Maggie?

Predictably (and conveniently for the drama), Jason and Fiona are put on the case and he's desperate to solve it because if he does his promotion is pretty much guaranteed. But he doesn't seem to have a clue he's investigating his own wife. Even though her behaviour should be a massive giveaway.

As the action moves from Bray to Sunderland to London and on to Luton, the untangling of the story (sometimes quite messily done) will take in a grisly post-mortem, a ripped up photograph, a cupcake baking session, a mullet worthy of Paul Chuckle, drug runners, sex traffickers, a lively game of hurling, further falsified identities, a nasty teacher called Katie 'Cunty' Ryan (Aiobheann McCann), and a tattoo of a very identifiable corvid.

The three kids will all develop their own storylines which run parallel to the murder hunt. The eldest, Derek (Rhys Mannion) is Shelly's stepson and he doesn't feel she loves him as much as she does the younger two. He's a skateboarder and a trainee stoner (who snorts at the description 'baked' on a tube of crisps) and he learns a very tough lesson about first love when he's dumped by Doireann (Grace Collender). A girl he goes on to, essentially, stalk.

He argues with his stepmum and tells her his dad sleeps around. Something she seems to already be aware of. Caitlin (Katelyn Rose Downey) is a sweet kid who loves dogs and choc ices but she's just started her periods and is also starting to wonder about her sexuality. The youngest of three is Niall (Aidan McCann) who suffers from cystic fibrosis for which he's teased and bullied mercilessly. Not least by Cunty's awful son Billy (Benjamin Bergin).

Things get even more complicated when a historical murder case in London is found to have echoes of Charlie's killing but when DCI Critchett (a very hammy, intentionally perhaps, Cathy Belton) tries to reopen it she's shut down by her superior Commissioner Grant (Steve Gunn), a man who looks so much like Baxter Dury I had to check IMDB in case it actually was him doing a cameo.

Back in Ireland, Shelly has befriended the American writer Matt (Trevor Kaneswaran) whose daughter is at school with Caitlin and Niall. Matt seems suave but he also seems a bit of a dick. He describes himself as a DILF and drinks whiskey with Shelly (who, to be fair, does love a drink - and a smoke - maybe some pills now and then) at 9.30am in the morning before making a firmly rejected move on her.

Matt's daughter, Emma (Nathara Dayananda) is a much more sympathetic character. Seeing off Niall's bullies, learning Gaelic, and raving about her native Wisconsin. On top of that there's a tough on crime politician back in the UK in the form of Rory Lynch, Charlie's brother (Niall Bishop), a stoner mate for Derek in Luke (Maeron Libomi), and a couple of potential witnesses in migrant worker Zelma (Ailbhe Cowley) and housekeeper Eileen (Orla Casey).

There's even a burning bible and a chance to learn the Albanian word for whore (kurve). It's a lot to take in and sometimes the daft beards, the oversized sunglasses, and the plot holes so big you could drive a bus through them sit uneasily with the general mood of foreboding and grisly flashbacks. Which, despite the daftness, Patrick Lavoie's eerie score does a great job of underpinning.

Less impressive are the supposedly cockney accents of some of the Irish actors playing Londoners (they're horrifically wrong, as if they're avenging those terrible Oirish episodes of Eastenders back in 1997). That's a lot of caveats yet somehow Clean Sweep (just about) redeemed itself. There's a brilliant spine tingler of a moment about halfway through when CCTV footage provides us with a crucial revelation and there's a lovely family scene when Derek sticks up for little brother Niall who then tells a story about the Irish Giant. Slainte!

But, always, at the heart of this drama is suspicion. Suspicion of partners, suspicion of parents, suspicion of colleagues. There's so much side eye action you could imagine the cast are paid a bonus every time they do it. Obviously the story has been conjured up entirely for this reason and if you don't take it too seriously it's a pretty thrilling ride. The big question, throughout, appears to be can we outrun our past or will it, no matter how hard we try, one day catch up with us and ultimately destroy us. Stay to the end to find out.