In terms of foreign language films at this year’s London Film Festival, there really are none better than Another Round. The latest collaboration between director Thomas Vinterburg and star Mads Mikkelsen is inventive, spritely and pulls off its innovative concept with style.

Another Round takes a long-held fantasy of hard-working professionals and runs with it: the idea that drinking on the job actually makes us work better. In scientific terms, our blood alcohol level is supposedly 0.05% lower than it ought to be, which is where Martin (Mikkelsen) and co come in – to put this to the test. As a group of laboured but somewhat timid high school teachers, alcohol is never too far in the background, and by bringing it to the fore it allows for some great moments to occur.

It’s a film that is often fascinating: seeing how this group of teachers become more vibrant and expressive truly makes for a great watch, which is illuminated particularly by a stunning lead performance from Mikkelsen, who transitions from quiet to charismatic (and beyond) with such fluidity and ease. The chemistry between the four participants is very bubbly, really feeling like a group of long-standing friends, with Vinterburg and Tobias Lindholm’s script delving deep into middle-aged ennui and the lengths people will go to find a new lust for life.

Yet the film certainly isn’t pro-alcohol at all: in fact, it’s at times quite a heartbreaking look at how their drinking impacts their lives and the lives of those around them. After a first half that feels like a big night out, the second half is definitely the hangover: Martin ends up drinking even when he doesn’t want to, egged on by his peers, and their increasingly dangerous dependence on alcohol leads to truly tragic circumstances. The way it handles the dark side of their drinking is a stark contrast to the rose-tinted glasses with which they first see the experiment – comparing themselves to world leaders drinking on the job – and Vinterburg’s ability to completely shift the tone on a whim is terrific.

It’s in this second half when Mikkelsen’s performance really steps up a notch: as he finds out some painful personal news, his range elevates to new levels, and we see Martin more angry than ever before, driven by rage and spewing sheer venom. He stands out in a cast full of great performances – with Thomas Bo Larsen the other highlight as Tommy, a football coach whose alcohol abuse goes even further than the others – and it’s thanks to these strong performances, and the chemistry between the cast, that the film is so enjoyable.

Yet despite being overbearingly bleak at points, the fun at the heart of Another Round is never lost. This fun doesn’t emerge from their drinking – as mentioned, the negative effects of alcohol are certainly made clear – but from the life they realised they were taking for granted, with an overall rejoiceful tone that is underpinned by a splendid final scene, with Mikkelsen doing something you certainly won’t have seen him do on screen anywhere else. There is still plenty to think about though: I’m still not sure if Martin is a good person or not, considering how reckless he becomes throughout the film, and whether the film overall agrees with their theory about the 0.05% blood alcohol level is something worth considering.

Another Round is one of those rare gems of a film where it manages to execute a truly fascinating concept – one that everyone has considered at some point or another – with skill and precision, never missing a beat and remaining consistently entertaining throughout. It’s a genuinely engrossing exploration of drinking and the normalisation of dangerous consumption habits, yet it’s also bubbly, heartwarming and anchored by a splendid Mads Mikkelsen performance. A true gem that should definitely be in with a shout this awards season.