​​Guilt series three review – this thrilling drama is back on form for its big goodbye

‘Everything is murky in this world,” said Edinburgh’s top gangster, Roy Lynch (Stuart Bowman), laying down a warning to one of his many innocent victims, “and you are lost within it.” That was towards the end of Guilt’s second season, when the programme got a little lost in the murk itself. But with a writer as fine as Neil Forsyth in charge, the third and (by Forsyth’s own choosing) final season of this mordant noir fable finds a way through.

Guilt began with squabbling brothers Max (Mark Bonnar) and Jake (Jamie Sives) accidentally running over and killing a man while driving home from a wedding. Their efforts to escape responsibility for what they’ve done put pressure on the old wounds in their relationship: Max the serpentine, polo-necked lawyer, with his fancy house and his belief that rules ought not to apply to him, was forever being tripped up and dragged down by Jake, a shambling, open-hearted record shop owner and failed musician whose simple view of the world often brought with it an uncomfortable moral clarity that didn’t fit with Max’s scheming.

Max and Jake’s Fargo-ish descent into farcical peril ended, in season one, with Max going to prison – featuring a last, long closeup of realisation spreading across his face as he was driven away, which paid homage to The Long Good Friday – and Jake, having sold his brother out, fleeing to Chicago to fulfil his dream of owning a dive bar. A second, almost Jake-less second season saw the ex-con Max, his old life gone, embroiled in a vengeful battle with the intimidating Roy and his even more intimidating wife, Maggie, a cardigan-wearing cobra played with calm relish by a magnificently against-type Phyllis Logan.

Guilt was still rich, gamey drama, written with a pitiless eye for human weakness and a savvy appreciation of the shame driving so many of its characters, torn between Edinburgh – where the crooks wear expensive suits – and its rougher port, Leith. Max and the Lynches had become Edinburgh people, but the stain of Leith refused to wash off. Yet without the sibling resentment, some of the show’s heart had gone, and its web of machinations and betrayals became hard to follow. At times even the excellence of the scripts were a drag: Guilt started to suffer from what you might call Succession Exhaustion, as almost every scene became an intense, extended two-hander, a psychological war stuffed with bitter epigrams and cruelly revealed secrets. Watching one epic verbal smackdown after another (and another) was a bit much.

As we rejoin it for the last death-waltz, Guilt is still skulking stealthily around Edinburgh’s underbelly. Maggie Lynch is still holding meetings, ie conversations where she threatens to kill someone, either in the city’s fanciest rooms or in disarmingly beautiful pockets of post-industrial wasteland. The soundtrack, still precisely curated for the enjoyment of discerning folk born in the 1960s or 70s, is populated by the Cramps, the Sensational Alex Harvey Band, the Mekons, Wire and the Stranglers.

Related: Mark Bonnar: ‘People say I’m in everything and they’re sick of the sight of me!’

But Jake and Max are reunited, the little bro along for the ride as Max engages in a final game with Maggie. A show that has always been about the impossibility of outrunning one’s past becomes more focused than ever on fathers and sons, mothers and daughters, childhood echoing into adulthood and people who can only play the terrible cards they were dealt at birth. There are new schemes afoot, too: a silver-smooth local banker announcing a lucrative deal, and teenaged drug dealers conducting a breathless chase through a Leith estate, both of which must surely end up being something to do with Max v Maggie. Old faces return when least expected; a face is finally put to a name previously only referred to, painfully, in passing.

Sometimes Guilt still gets bogged down in its own complex ambition. As the end draws near and the entire cast of characters simultaneously face a life-defining choice or crisis, keeping track of who is double-crossing whom becomes virtually impossible, and some of Forsyth’s weighty dialogue is still a burden. A trip to a loch inspires a clanging analogy about how the watchfulness of a fisher might be applied to the Edinburgh/Leith criminal underworld, while Maggie has one line that tips her from controlled menace into camp villainy.

Despite that, Phyllis Logan is the perfect antagonist: omniscient and omnipotent in the manor she runs, with a jagged personal brittleness beginning to poke through her armour. Opposite her, Bonnar has never been better in a role that lets him display his two great strengths – hypnotic charm and snarling, desperate malevolence – at the same time. They have made Guilt’s trip around Edinburgh’s dark corners a rare thrill.

• Guilt is available on BBC iPlayer and airs on BBC Two in the UK from 27 April, with an Australian screening date to be confirmed.