Like its central character, the final episode of Blackout ends up teetering on the edge of disaster in an unhappy mess of good intentions gone awry.

Yet while Daniel Demoys (Christopher Eccleston) was pretty much doomed from his first appearance, the story of his journey to disaster was full of promise – which makes it unhappily ironic and doubly disappointing that while he ultimately manages to salvage something faintly noble from the wreckage of his life, the drama depicting it does not.

Part of the problem is the paucity of plot left over for Episode 3. The central story doesn’t stretch to three hours’ worth of television, so the gaps in the last instalment are filled with protracted pontificating – mostly from Jerry Dorans (Ewan Bremner), wannabe-Urquhart mouthpiece for the bastardly corporation, Danto Global, who was apparently as much an idealistic man-of-the-people as Demoys, back in the day, although this seems about as likely as Spud getting that job in Trainspotting after turning up to the interview on speed – and lots of out-of-focus, slowed-down shots of Manchester’s streets at night that look like they were culled from Cracker outtakes.

The cumulative effect is the pace slows to a crawl, something emphasised by the way Detective Bevan (Andrew Scott) spends half the episode dragging his bloodied and battered hide around the streets, popping paracetamol and looking like a cut-price Krycek from The X-Files.

There are also belatedly-introduced subplots that feel tacked on (Demoys’ son Luke has a breakdown and visits Branka Katic’s all-seeing, all-knowing nurse Donna for some spiritual succour), characters brought to prominence too late for their comeuppances to feel important (we’re looking at you, Detective Griffin) and – worst of all – rapid resolutions to character arcs that don’t fit.

Ruth Pulis (Rebecca Callard) is hastily dispensed with after slapping the murderous mayor around the face for killing her dad (‘You might not be going to prison, but I hope you go to hell’) while Sylvie (MyAnna Buring) mopes around her flat after being dumped by Demoys before undertaking a U-turn the government would be proud of and reconciling with her husband. Neither of these outcomes seems right for the characters and the whole impression one is left with is of half-finished things rushed to a conclusion, like a restaurant forced to stick to its planned opening night even though the paint’s still wet on the walls and the kitchen resembles a building site.

It’s not all bad, of course. The cast are uniformly excellent in spite of what’s going on around them and there are some affecting scenes with the Demoys family all together – particularly their final meal together and the abrupt switch from warm, knockabout, familial chatter to tearful farewells, the younger actors (Olivia Cooke, Oliver Woollford and Lorenzo Rodriguez) matching Eccleston and Dervla Kirwan in their intensity and believability. It’s almost enough to make up for the frankly preposterous way the Danto logo turns up everywhere, implying that they’re Manchester’s equivalent of Skynet from Terminator.

Almost, but not quite. The promises of the first episode’s exploration of alcoholic morality and the second part’s lurch into conspiracy thriller aren’t delivered upon, and by the time the final (overly drawn-out) scene fades to blackout – groan – the overall feeling is mostly one of relief that it’s over. What a pity.

Aired at 9pm on Monday 16th July 2012 on BBC One.

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