The Substitute review – watchable Argentinian teacher drama fails to inspire

The curse of cinema’s substitute teachers is that they are forever doomed to serve as a proxy for the writer’s fantasies. Detached figures swanning into run-down schools and saving the lives of a few troubled teens in the process, they're the perfect cipher for any egotist’s savour complex. It’s a concept with as much grounding in reality as your average superhero film, because, as anyone who has ever been to an actual school knows, the reality of substitute teaching is one of being a perpetual doormat for a group of unruly kids.

That doesn’t stop Diego Lerman, the writer-director of The Substitute, from trying anyway. He brings an observant, politically-minded eye to this milieu, a rough neighbourhood somewhere in the outskirts of Buenos Aires, into which failed novelist-turned-substitute teacher Lucio (Juan Minujín) arrives. His attempts to bond with teens and engage an interest in literature fall mostly flat. It's only when a major drugs bust occurs in his class that the narrative gears start to turn.

The question arises as to whether the drugs were planted and what this has to do with the incumbent law-and-order mayor and the local drugs kingpin, both running for office and seemingly ready to use the school as a pawn. To make matters more complicated, it appears Lucio’s dad, a community organiser nicknamed “The Chilean” (Alfredo Casto), may be peripherally involved.

Far from being able to provide much inspiration or knowledge to the class, our eponymous temp instead has to find a way through the mud of a political and social quagmire. Unable to inspire minds through rhetoric and teaching, Lucio instead has to turn to physical action to try and create effective change. Here, too, he is often woefully clumsy and heavy-handed, his middle-class demeanour woefully at odds with the barrio crowds that surround him.

This, then, is the central idea of the film: the contradiction between pleasing and idealistic rhetoric, and the physical activity, organisation and doggedness that is required to make such rhetoric a reality. But once the film sets up this concept, it refuses to do much with it, bogging our protagonist down with a series of redundant side quests; he pressures his 12-year-old daughter to go to an elite school, oblivious to the impact on her mental health; he has a romantic dalliance with another teacher, which is never mentioned again; his father has to battle cancer as well as gangland politics. This is the sort of film that is both underwritten and overwritten at once.

The Substitute is at its most effective when finding eloquent visual touches to elevate its ideas: Lucio’s face obliterated by a frosted window, or a one-take chase through back alleyways, or the contrast between the teacher's cold modernist apartment and the rundown school he works in. And yet, these flashes of inspiration aren’t allowed to penetrate with much impact, The Substitute often retreating to classroom polemics. Ironic that a film built around the saying that actions speak louder than words is so shy about action itself. This is not a wholly bad film whatsoever – but a bit of focus and purpose could have turned it into something greater than the sum of its parts.

The Substitute is released in UK cinemas on 20 January.