Life is rarely kind to Nessa Stein.

The little girl who saw her daddy stabbed in the neck by a waiter (for being boss of an arms company rather than failing to leave a decent tip) has grown up rich and successful as a result of running the family business – but it has come at a heavy price. Although she and brother Ephra have transformed the Stein Group into a more philanthropic organisation, the legacy of its gunpowdered past casts a long shadow.

Nessa was once taken captive in Gaza – as a result, her personal security is tighter than George Osborne at a railway ticket office. She sleeps in a panic room fitted out like a toilet on the Millennium Falcon, she has to shag her bodyguards to unmask them as MI5 operatives (although this has obvious benefits), yet her enemies can still get to her. Worse, they’re aware of the skeletons that have hung in her cupboard since her time as a hostage.

‘We know your secret, Ms Stein,’ one of the kidnappers of Kasim – son of confidante and family nanny Atika – reveals. The abduction is part of a plan to bring the Stein family down, but so far the nature of the scheme, like Nessa’s dark secret, remains anyone’s guess.

What’s easier to fathom is why Hugo Blick was so keen to have Maggie Gyllenhaal portray his complex and conflicted main character: she’s simply breathtaking. Nessa struggles to maintain her icy self-possession in moments of extreme pressure or passion, but Gyllenhaal’s performance remains as impeccable as her English accent. Not even the slightly florid Lord of the Rings-style voiceovers at the beginning of each instalment make Nessa any less convincing or compelling.

Equally impressive is Stephen Rea as Sir Hugh Hayden-Hoyle, outgoing head of MI5’s Middle East division. With a face like a worn-out pair of shoes and a voice quieter than Bob Harris with laryngitis, Sir HHH does not conform to the Ian Fleming stereotype of a superspy. But as his scalpel-sharp deconstruction of Rebecca Lantham’s (Julia Montgomery Brown) flimsy pretence at being the mistress of supposed suicide Samir Meshal proves, he’s right on the money.

‘We fucked like rabbits,’ she claims, trying to embarrass her interrogator, only for Hayden-Hoyle to calmly reveal that Meshal was clinically impotent due to prostate cancer. He’s also not averse to a touch of wry ribaldry of his own: ‘What’s the going rate for an ageing penis?’

Worse is to come for Rebecca – actually an FBI agent named Tracey Vorman. With her cover blown, Tracey becomes expendable to her paymasters in the US Government and is shot dead by a treble-bluffing, wisecracking taxi driver. ‘You wanna catch a turkey, honey, just blow its head off,’ he quips … shortly before getting shot himself. But who is efficiently cleaning up these loose ends? Is it the CIA covering their asses, the British exerting territorial rights, or someone else entirely?

A conventional thriller would toss off this kind of subplot in a 30 second pre-title sequence; The Honourable Woman devotes almost a third of the episode to it. Like everything else in this exceptional piece of television, it’s all the better for being given room to breathe.

Airs at 9pm on Thursday 10 July 2014 on BBC Two.

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