Wolf review: A middle-class family (and their dog) are terrorised in one of the most harrowing dramas in years

This new BBC thriller, based on the novels of Mo Hayder, is highly compelling – if not for the faint of heart

Once upon a time, a television announcer would introduce a series such as Wolf with a sombre warning that it wasn’t suitable “for viewers of a nervous disposition”. That sounds a bit antique now, obviously, in a world of infinite internet videos and livestreams of mass shootings. But, after steeling myself through the entire six-part drama, I really do think the BBC should find a way of cautioning its licence payers about what is about to arrive in their homes. Wolf is horrific, frankly, and much the most harrowing thing I’ve had to watch for some many years.

That doesn’t make it “bad” television – far from it – but it is very strong stuff. I kept having to remind myself that it’s all tomato ketchup and fiction, and imagine the crew joshing over lunch in the canteen bus, but to little avail. Appalling violence of an apparently motiveless kind is its leitmotif, and if I told you it contains multiple scenes of extreme mental and physical torture, animal cruelty, giblets strewn everywhere like Christmas tinsel, gore, references to paedophilia, marine animals in unlikely settings, sex in pub toilets, drugs, a frightened Bichon Frise and some terrible dancing, I would still consider you inadequately prepared for what was to assail your eyeballs. Much of the action is set in Wales, which also gives Wolf a kind of Wicker Man/Clockwork Orange-meets-the-Eisteddfod vibe, which is less fun than it sounds. It’s not an easy watch, and 9pm is far too early for it, even if you’ve got a professional counsellor accompanying you on your journey into fear.

Viewing discretion is highly recommended, therefore, but so is sticking with it – if you’ve the stomach for a fright – because it’s also highly compelling, a real horror-thriller in the best tradition, and brilliantly directed (credits to Lee Haven Jones and Kristoffer Nyholm).

Based on a series of novels by the late crime writer Mo Hayder, there are basically three interwoven storylines, so as well as the audience needing to process constant sadism, the plot is a bit tricky to follow. The central, unifying, figure is DI Jack Caffery (a finely understated portrayal by Ukweli Roach), a young detective who is obsessed by the abduction and loss of his little brother when both were children. A neighbour – a caricature seedy paedophile named Ivan Penderecki (Anthony Webster) – was arrested and eventually convicted of other offences against children, but not for what happened to Jack’s brother. The neighbour is fresh out of prison, and Jack watches him obsessively from the window in his brother’s room, preserved as shrine. Such behaviour causes friction with his wife, Veronica (Kezia Burrows), whose cancer diagnosis adds to their relationship difficulties.

Caffery himself is recently returned from Monmouthshire, whence he fled because of the lingering pain of loss. While he was in the police there, he helped investigate a double, ritualistic murder of teenagers, seemingly motiveless. Five years on, Jack finds himself back there, trying to find a witness who might help him solve the mystery of his brother’s disappearance, and escaping the newer anxieties of his current relationship with Veronica.

As he tracks down the potential witness, a man who knows a man who knew and attacked Penderecki in prison, Jack gets entangled in a strange new crime, and the one that is the main focus for the series: the imprisonment, kidnap and torture of a well-off family from London at their remote holiday home. The Anchor-Ferrises are the stunned and bewildered victims, being mother Matilda (Juliet Stevenson in excellent form), poorly father Oliver (played by Owen Teale with touching vulnerability), and their distraught young adult daughter Lucia (Annes Elwy).

A pair of men masquerading as detectives, “DI Honey” (Sacha Dhawan) and “DC Molina” (Iwan Rheon) trick their way into their house, and then proceed to terrorise and abuse the family and the pet dog; the assaults and constant threat of rape punctuated only by the pair’s ugly mockery and quips. With writer and adapter Megan Gallagher, Dhawan and Rheon are to be congratulated – if that’s the right expression – for exploring new depths in the human condition previously only seen in the traumatic sado-psycho-drama Austrian modern classic Funny Games (1997, and re-made in 2007).

So evil are the Honey-Molina duo, and so keen on inflicting suffering for their own sheer amusement, that we really root for the family to escape and survive, and thus – well, I speak for myself – the viewer feels morally obliged to share their pain over the succeeding episodes in the hope of eventually seeing justice done. I can’t tell you if they or Jack succeed, but I can say that you will definitely be as surprised as you will be horrified as this superbly crafted intricate tale twists its tail.