Beast is a crisp, clinical and efficient genre film, about a rogue lion stalking four characters on safari in South Africa – Nate Samuels, a doctor played by Idris Elba, his daughters Meredith and Norah, played by Iyana Halley and Leah Sava Jeffries, and his friend Martin Battles, a biologist played by Sharlto Copley. Nate grew up in South Africa, and met his wife there, before they relocated to the United States together. Shortly after they separated, she contracted terminal cancer, and died just before the film begins, turning this return to South Africa into a journey of healing for Nate and his two daughters, a way of processing their grief.

There’s a symbolic story here about Africans becoming African Americans, and then returning to the motherland – the first photo that the girls see upon arriving at Nate’s old house is a photograph of their pregnant mother. Similarly, there’s a commentary upon poaching and trophy hunting as the latest horizon of colonialism. Martin, Nate’s friend, helps protect lion packs, to the point where he can approach them unarmed. He’s also engaged in a covert war with poachers, who have started expanding their net to take in lions, targeting whole prides in order to satisfy the market for teeth, claws and bones. When the rogue lion emerges, it’s as a direct result of these poachers, who have split up his pride, forcing him to transgress normal boundaries and prey on humans instead. There’s a recurring comparison between this lion without a pride and Nate’s own fractured family, especially since his older daughter blames him for their mother’s death, making it difficult for him to play the fatherly provider.

Yet while these conceptual possibilities percolate through the script, Beast is a genre film at heart – concerned, first and foremost, with the pragmatics of survival once the four main characters are trapped in their jeep by the rogue lion. This is where the film really comes into its own, as director Baltasar Kormakur transforms the grasslands and mountains into a liquid surface that ripples and quivers in response to the lion’s passage through it. Martin first encounters the lion at the cusp of a river, and initially mistakes it for a crocodile, the other apex predator in this ecosystem. Then, the lion drags him to an island in the middle of this river, and leaves him there as bait for Nate and his family. Later on, Nate has to immerse himself in this same body of water to retrieve a pair of keys from a poacher, all as the lion stalks and sneaks around its shores, as it does for much of the film. Some of the eeriest sequences see the lion move far more fluidly than its bulk would suggest across this river too.

This synergy between lion and river is the first step in liquefying the African landscape. Suspended in the swampy zone between dry and wet land, it becomes an alien gaze that Nate and his family have to learn to discern from afar once Martin fails to contend with it up close. To that end, they start to scan the landscape for pockets of unusual quiet or shade in the noonday sun, keeping their eyes peeled for “movement, anything that casts a shadow.” In time, this expands to a preternatural sensitivity to any slight disruptions in the ecosystem, much as Kormakur increasingly opts for long tracking shots that curve flamboyantly around trees, rocks and other objects, both evoking the mobile sightlines of the lion but also collapsing the landscape into a flux of light and shade that shifts with the slightest inflection.

Beyond a certain point, Kormakur opts for spatial fluidity over spatial intricacy, perhaps explaining the almost deliberate way that the film pulls back from some of the possibilities of these early scenes. One sustained sequence revolves around a hunter’s blind, a tower on the horizon that we glimpse from a distance, and yet the film never returns to it. Similarly, the film ends at an old colonial school perched on a mountain, but doesn’t take time to explore its spatial parameters before the lion inevitably shows up. Even the crocodile never recurs, despite the fact it seems to live and hunt right on the threshold of the lion’s territory. These decisions seem to reflect Kormakur’s desire to avoid panoramic or vertical vantage points, since that would be to disrupt the undultating fluidity of the whole, while keeping the lion firmly at the centre of this watery world, which only intensifies with the arrival of nightfall.

This aesthetic is all the more impressive in that we see the lion in its entirety early on. Rather than concealing the monster, Kormakur presents it as embodied and disembodied at the same time – both the fully-fleshed out beast that keeps returning to attack the family and the mercurial play of shadows that deepens as the sun goes down. The elusive space between real and virtual threats, physical and psychological danger, propels the film into some really effective CGI work – or, rather, makes the inherent artificiality of CGI a part of the horror, since this lion is always simultaneously present and absent, distinct from the landscape and subsumed into it. Kormakur continually contrasts the stark physicality of the African landscape with the virtual sphere that the characters are trying to wrest from it, or graft on top of it. Nate’s daughters epitomise this push-and-pull – Norah is shocked that there’s no cell phone reception, Meredith prefers analog photography – while the lion’s movements push them to the cusp of CB radio reception, keeping them just within range of a faint signal.

The film ends, appropriately, at the old colonial school perched in the mountains. Classic colonialism has become neo-colonialism with the transformation of these classrooms into a poachers’ lodge, adorned with macabre corpses that haven’t yet been cemented into trophies. Caught at that threshold between old and new ways of conquering the continent, and in the brief lull between visits from poachers themselves, Nate draws the lion to another threshold, engaging it in a battle that takes them down the mountain, and onto the cusp of another pride, whose own lions gradually come in to finish off this rogue individual. It’s a poetic ending for a film that hangs between real and virtual spaces, colonised and wild space, ushering in the last tracking-shot, which takes Nate through a dreamlike village to make peace with his wife, clad in traditional South African gear. Poetic but modest, like Beast itself, which is content to rotate through its genre cues while letting the big ideas resonate as they may.