County Lines review – dark tale of the burdens borne by drug mules

“County lines” is slang for a new UK crime phenomenon that is basically as old as the hills: the targeting of vulnerable teenagers from the big city, generally ones absent from school and without stable family support, and using them to traffic drugs out to the provinces via solo train journeys – an invisibly discreet method – and then traffic the resulting cash back. It’s about drug mules, those age-old human beasts of burden, and about using children as the disposable footsoldiers of crime, which Dickens would have recognised. Henry Blake’s debut movie about all this, developed from a short made in 2017, is focused, compassionate and well-acted: a shocking social-realist drama-thriller.

The victim-hero is 14-year-old Tyler (played by Conrad Khan) who lives at home with his mum Toni (Ashley Madekwe) and kid sister. He’s been excluded from school for fighting (Toni was once in trouble while a pupil at the same school) and crucially emboldened to do this by an earlier bullying incident in a chicken shop, when a total stranger stepped in to help him.

This was a guy in his early 20s: tough, confident, kindly, clearly the kind of role model that young Tyler hasn’t encountered since his dad ran out on the family. He is Simon, coolly played by Harris Dickinson, who starts giving Tyler lifts in his nice car, letting Tyler see his expensive watch, taking him out for meals and letting him talk about his worries. Soon, desperately overworked Toni loses her cleaning job and Simon tells Tyler he must step up to his responsibilities and be a man: which is to say, Tyler must run drugs down to Canvey Island in Essex on the train and help sell them in a world of Hogarthian violence and squalor.

The first “meal” scene with Tyler and Simon is very interesting: it takes place in another down-at-heel burger place. (Later, Marsh will show Tyler’s wonderment and intimidation in seeing Simon in a much classier restaurant with his partner and child – and Simon’s intense irritation at this low-ranking subordinate presuming to contact him there.) Simon is grooming Tyler, and allowing him to experience, perhaps for the first time in his life, the pleasure of being listened to and treated with kindness. But the film shows how the conversation is provisional, exploratory. Simon is sizing Tyler up: assessing his suitability for employment. How much responsibility might this kid be given, if any?

Related: County Lines' Conrad Khan: 'Kids with no emotional support are easy prey'

Interestingly, that first intervention in the chicken shop was not necessarily part of a master plan. Simon doesn’t even remember Tyler when he offers his shy thanks the next day. Getting involved in potentially violent situations with school-age kids that he’s confident of beating in a fight is something that Simon does almost without thinking. But, like career criminals, he can see how to create and enforce the bonds of loyalty, and of course his friendly mask is soon to be removed.

County Lines is a film that doesn’t run along the usual rails of a gangster thriller. You might, for example, expect to see cycle-of-abuse evidence, signs of Simon’s own erstwhile innocence or victimhood, and then indications of how Tyler is coming of age in this nauseous business: becoming more ruthless and more professional, or maybe even superseding his boss. Blake doesn’t do that, although he certainly shows how Tyler is becoming more indoctrinated into the world of brutality, a trainee abuser who assaults his mum. Instead, County Lines shows us something realer and more banal.

For all the violence and the machismo, it is the woman who finally has to clean up the mess. Tyler’s mum must look after him, take him to hospital and take the measures necessary to settle his outstanding problems with Simon, who has naturally revealed himself to be the bully-in-chief. County Lines has excellent performances from Khan, Madekwe and Dickinson, and also Anthony Adjekum as Tyler’s teacher Laurence, one of the few people who speaks to him with genuine sympathy.

• County Lines is released cinemas and on digital platforms on 4 December.