What does 11-year-old Harry want to be when he grows up? Footballer? Software coder? He shrugs. Dunno. “I don’t want to be living on the streets poncing money.” Harry is a white working-class boy: the demographic that gets the worst GCSE results. His dad left school illiterate, so did his grandad. Not yet a teenager, Harry can already picture a future in which he is homeless – it’s heartbreaking. With this unobtrusive, tightly focused fly-on-the-wall documentary, directors Edward Owles and Jaime Taylor follow the efforts of Harry’s school, the Reach Academy in Feltham, west London, to get him back on track in years seven and eight.

At a staff meeting, a teacher talks about pupils arriving in year seven not able to tie their shoelaces, tell the time or spell their names. Reach has a track record for progressing disadvantaged kids, using an approach based on high expectations, “warm-strict” discipline (kids shake hands with their teachers in the morning) and creative lessons (an English teacher in a baseball cap raps “grammar time” to the rhyme of “hammer time”). Sophie, newly qualified, is giving Harry literacy lessons with levels of patience and stamina that left me wondering about the burn-out rate among staff – I didn’t see a single teacher who looked over 35.

You can imagine this being made into a warm-hearted Britflick with a punch-the-air ending as Harry aces GCSE English. The reality is a tougher. There are victories along the way, such as a 10/10 a spelling test. But, as he slouches over a desk, it’s as if Harry has already checked out of school. Lessons bore him stupid. There are no simple solutions.

In a recent interview, Reach’s head spoke about wanting to be the first school to provide parenting classes from birth. But what you do get here to cheer you up are scenes of teenagers being brilliant. A girl mutters: “Shakespeare is really confusing. Why can’t he just use English?”