If you’re a parent to a school-age boy, I don’t know whether I should advise you to watch Adolescence (Netflix) immediately, or avoid it at all costs because it will chill your blood. It is a drama so quietly devastating that I won’t forget it for a very long time.

A 13-year-old boy in Yorkshire is arrested on suspicion of murder. The victim is a girl at his school, stabbed to death the night before. Police batter down his door in a dawn raid, and his shell shocked parents – dad Eddie (Stephen Graham) and mum Manda (Christine Tremarco) – follow him to the police station. “Do you believe me that I’ve not done anything?” the boy, Jamie, desperately asks his dad. “Of course I believe you,” says Eddie. “You’re my son, aren’t you?”

This does not play out as a crime thriller. Nor is it a police procedural, although the first episode very much goes into details of what happens when a minor is arrested for a serious crime (the mug shots, the medical examination, the strip search). It’s not really about knife crime. Rather, it’s an exploration of the pressures on boys today, including the malign influence of social media and some of the nonsense about what it means to be a man. Bullying isn’t new, but being mocked online is a modern horror. And parents, in many cases, are oblivious.

The writer is Jack Thorne, doing double duty on Netflix after the launch of his other drama, Toxic Town. The format is unusual. Each of the four episodes is self-contained and filmed in one continuous shot. Episode one is Jamie’s arrest and initial police interview, featuring Ashley Walters as the detective. Episode two is set in the children’s school, where the pupils’ behaviour is horrendous and the teachers are flailing hopelessly. Episode three is a meeting between Jamie and his appointed psychologist, played by Erin Doherty (the actress is the one person here who doesn’t fit the realistic tone, delivering her lines as if she’s in a play). The final episode takes place at home, where the family attempt to maintain normality while Jamie remains in custody.

At times, the “one-shot” direction can feel like a gimmick – highly effective for one or two moments, but I’m not sure this drama would really suffer from being filmed in the standard way? The acting, though, is phenomenal.

Adolescence is a masterclass from Stephen Graham. Of course it is. Graham is the best actor working today. There are stretches of time when he walks wordlessly through a DIY centre, or we only see the back of his head while he’s driving a van, and he’s conveying more emotion than 99 per cent of other actors can manage when they’re talking.

Walters is great, his feelings about arresting a boy so young demonstrated in one tiny gesture, when he briefly puts a hand on Jamie’s shoulder as he’s taking him to be booked in. But the truly remarkable performance is from newcomer Owen Cooper as Jamie. Cooper was 14 when he filmed this (he’s 15 now). He moves between vulnerability, anger, bravado and fear. What he does here is astonishing. “I still see that little boy – a bit gormless, swinging on the monkey bars, drawing pictures of monsters,” Eddie says to his wife. Thanks to Cooper’s performance and Thorne’s writing, we can still see that boy despite the terrible crime of which he is accused, and wonder where it