Dublin Murders, Series Finale, BBC One review - eerie detective drama grips tightly

You wouldn’t expect a drama called Dublin Murders (BBC One) to be a laugh a minute, but the cumulative anguish, menace and torment of this eight-parter made it almost unbearable, even if viewers were thrown a tiny scrap of hope in the final frames.

Adapted by screenwriter Sarah Phelps from Tana French’s novels In the Woods and The Likeness, it was (mostly) the story of detectives Cassie Maddox and Rob Reilly (Sarah Greene and Killian Scott, both consistently impressive) trying to solve the murder of aspiring young ballerina Katy Devlin while struggling with traumas from their own pasts.

The disappearance of two children in a forest two decades earlier, of whom no trace had ever been found, brooded eerily over the narrative, more like a historical curse or fairytale (the Erl-King myth was specifically invoked in symbols discovered at a nearby archaeological site) than a crime capable of a conventional resolution. As an older detective working the case had written, “there’s a darkness here… those children were taken as a tithe. We’ll never find them.”

Yet the drama was also grounded in the daily procedures of police work and the often abrasive relationships between the officers, while its setting in 2006 placed it in the midst of Ireland’s then-current economic boom. A plotline about an unnecessary motorway being built, mafia-style, with misappropriated public funding gave the detectives plenty to puzzle over, since it involved the father of the murdered girl, but in the end proved to be a misdirection from the core of the story.

There were some head-scratching anomalies en route. The chunk of plot concerning Daniel March (Sam Keeley) and his odd little house-full of needy disciples – derived from The Likeness – never felt perfectly aligned with the In the Woods material. The way that Reilly managed to conceal his identity as a prominent person of interest in his own investigation was a major credibility-stretcher, while Maddox’s undercover mission to impersonate her own double, Lexie, teetered a little too far out on a limb for comfort. Nonetheless, Maddox’s confrontation with her dead doppelganger in episode three was a real heart-stopper.

Yet ultimately, it all helped to build the haunting ambiguity of the piece, where the ghosts from the past were mirrored in a treacherous present where fact and illusion became inseparable. Melancholy landscape shots, claustrophobic interiors and Volker Bertelmann’s disturbing soundtrack intensified the effect. There wasn’t much light relief, but Conleth Hill’s irascible Superintendent O’Kelly was a treat, and I enjoyed the shameless cynicism of Detective Frank Mackey (Tom Vaughan-Lawlor, pictured above).

• More TV reviews on theartsdesk