Insomnia review: The soundtrack does the heavy lifting in Vicky McClure's limp and ponderous spine-chiller

As Vicky McClure sleepwalks around her immaculately Farrow-and-Balled home, the subtitles try to tell us that the music is “tense”, “suspenseful”, “eerie” and, best of all, “creepy and pulsating”.

Largely though, the soundtrack is guilty of over-selling the drama, as many sequences simply involve McClure's troubled hotshot lawyer and mum-of-two walking about – whether through porcelain-tiled offices, art deco hospitals or, in some cases, shin-deep in a lake.

McClure is Emma, desperately trying to overcome a chaotic childhood to become a success both in her career, and in her family life.

Being a hotshot lawyer, Emma's husband Robert (The Gold's Tom Cullen) is a stay-at-home dad and part-time artisan carpenter, looking after winsome moppet Will and narky teenager Chloe.

Unfortunately, her impending 40th birthday is sending Emma – and her family, it seems – into a tailspin, possibly connected to her mother's mental breakdown just before she turned 40.

This week's first three episodes took their own sweet time to get going, with lots of unconnected plot strands set up without looking like they're ever going to tie together.

There's Emma's mum, and her possibly suspicious death sparking a police investigation.

There's Emma's work, and a partnership at her high-powered law firm – you know it's high-powered because the boardroom has a view of St Paul's – being dangled in front of Emma's face.

But that's imperilled by a complicated saga of a messy divorce and a 'white whale' of a client Emma's smarmy boss Angus (Anthony Calf) is trying to land.

Then there's Emma's sister Phoebe (Leanne Best), who has just turned up out of the blue, teenager daughter Chloe's catastrophic love life and son Will's penchant for drawing scary, bog-eyed ladies in his school workbook.

All of this is played against the flashbacked backdrop of Emma and Phoebe being terrorised by their mum, who keeps repeating a series of seemingly random numbers, rattling the doorknobs and inviting an invisible child to come out of the understairs cupboard.

Surprisingly, with all this going on, Insomnia suffers from long periods when nothing happens.

Emma stalks about the office, or looks worried, but for the most part we see repeated instances of her sleep-walking around the house in a repeat of her mum's door-rattling night-time perambulations.

Meanwhile, she frets over whether her mum's history is repeating itself and becomes increasingly paranoid – but just because she's paranoid doesn't mean they're not out to get her.

Or does it?

Yes, it's one of those shows. Chloe is having an affair with an older man... or is she? Weird new client Caroline (Lyndsey Marshal) is a good person.. or is she? Sister Leanne has good intentions... or does she?

Meanwhile, you're waiting around for answers which don't come, watching yet another flashback of young Emma and young Phoebe sitting on the landing watching their mum reciting those numbers like a lank-haired, white-nightgowned Carol Vorderman.

Meanwhile, some of it comes across as unintentionally comic – particularly when Emma comes to in a start to discover she's sleep-walked into the massive lake at the back of her house, or when Phoebe is trying to tell that her mum's illness is not passed down through the family.

“There's no such thing as bad blood,” she insists, “you're not a werewolf.”

And all the while, that music is trying to ratchet up tension that the drama – orginally shown last year on Paramount+ – itself just doesn't seem capable of emulating.

In the end, Insomnia is more in danger of sending you to sleep.