Welsh noir is on the rise, with shows such as Hinterland, Mudtown, and Hidden diving deep into the dark side of the national psyche. Pick of the bunch is the grippingly gloomy The Light in the Hall (Channel 4, Tuesday, 9pm) a thriller so good S4C and Channel 4 have made it twice over, in Welsh and English. The English-language version of series two is now upon us, and catches up with the story of butcher’s shop employee turned budding journalist Caryl Huws, as she is drawn into a murky and very noir conspiracy involving a fatal bombing 30 years earlier by eco-terrorists. The evocative setting is the fictional Llanemlyn in southwest Wales – the archetypal small town where curtains twitch, neighbours talk behind one another’s backs, and people are nipping off at night for forbidden assignations. Huws (Sian Reese-Williams) has worries of her own. Eager to break into journalism, she has been promised a job at a local newspaper provided she reel in a big story. As luck would have it, one has just fallen into her lap. In 1995, a local man, Rhys (Mark Lewis Jones), was convicted of killing his cousin when the latter’s plans to bomb a controversial reservoir went amiss. Rhys has always protested his innocence, claiming he was framed for a crime he did not commit. But the locals aren’t buying it: they point and stare as he goes about his business, and he’s barred from the local pub. In a convenient twist, he is out of prison just as plans are ramping up to expand the reservoir that was the target of the bombing in the mid-1990s. The community is divided, with younger people prepared to be arrested to stop the development and their parents largely determined to keep their heads down and hope for a quiet life. The best thrillers lean into the ambience of their setting, and that is the case here. Filmed in the market town of Llandovery, The Light in the Hall: Still Waters oozes atmosphere and reminds us that the Welsh countryside is the perfect backdrop for a tale of skulduggery and conspiracy. There are echoes of TG4’s Irish-language crime show Crá, which made the most of the rural-gothic splendour of the Donegal outlands. That series offset the grim subject matter with quirky humour whereas The Light in the Hall stays in the same ominous register throughout. Some viewers might find that suffocating: you can, it turns out, have too much of a gloomy thing. But The Light in the Hall earns its mournful tone – an achievement all the more impressive when you consider the cast had to film it twice over, originally in Welsh and then in English. In either language, it weaves a dark and compelling spell.