“You look like a gangster,” a man known only as “X” says to his partner-in-crime Lukas as the two wait for directions on their latest job in a scene from “When Lambs Become Lions.” It is before this point in Jon Kasbe’s bracing feature debut that you suspect you’re watching a real-life incarnation of Michael Mann’s “Heat” taking place in Northern Kenya, but when X adds about Lukas, who’s wearing reflective sunglasses and taking long, deliberate drags off a cigarette, that he looks like Robert DeNiro, your suspicions are confirmed.

Visually, Kasbe invites such comparisons to Mann, filming in a deceptively loose shooting style in a wide open frame where the implications of realism provided by a jittery camera can give way to stoic portraiture when it is allowed to sit still. But whereas Mann and others have borrowed documentary-style techniques to create the facade of naturalism, “When Lambs Become Lions” comes off as a “through the looking glass” moment, as its sleek, sophisticated storytelling makes a nonfiction thriller almost too good to believe, with scenes covered and edited as they would be in any traditional drama and a driving narrative where all its loose ends tied up at the end of a tense 80 minutes. While bearing none of the aesthetic messiness that traditionally comes with tracking real life, “When Lambs Become Lions” saves it for the ethically murky territory it enters by making X one of its central figures, joining him as he provides for his family through the illicit ivory trade in Africa.

Although X finds it distasteful to kill bugs, he has no issue with assigning Lukas to kill an elephant, which can bring up to 200,000 schillings for its tusks in a place where other means of making money are sparse and far less lucrative. While X knows this from his own experience, Kasbe draws a parallel for an audience in also following Asan, a local ranger tasked with preventing poachers such as X from killing elephants and other wildlife for profit. Morally, Asan can rest easily at night, but still he’s not getting much sleep, with his latest paycheck at least two months late with a new baby on the way and reminders all around that what he does is dangerous, whether it attending a funeral service for a fellow ranger who was murdered by the poachers or encounters where violence is deployed to bring them down. Naturally, the two men’s paths cross and it’s a tribute to Kasbe, Freddy Shanahan, and Caitlyn Greene, the trio who picked up a much-deserved prize for best editing at the film’s recent bow at Tribeca, how effortlessly the film builds them up as equals by the time they finally encounter each other onscreen for the first time, creating a tete-a-tete with all the gravitas of…yes, the famed DeNiro/Pacino diner scene in “Heat.”

It may be unsettling for some to give X the same consideration – and by extension, sympathy – as they might have for Asan as he plots the murders of innocent animals, Kasbe’s stroke of genius is showing how easily one could fall into a life on the right or wrong side of the law in a place where economic opportunity is limited if it exists at all, and “When Lambs Become Lions” clearly articulates the men’s divergent motivations that are born out of the same survival instincts. While staying alive will remain a concern for them both long after the cameras leave, Kasbe turns a study of men driven to desperate measures into an unexpectedly lively and crackling drama, turning a conversation often too mired in extreme positions to show how culturally ingrained such criminal activity has become without ever resorting to shocking imagery to make its point about poaching. Instead, it’s a shock to the system — about the system that causes it to persist, and in offering a ground-level view of the seemingly futile fight to protect animals, its consideration of the humans caught in the crossfire is quite compelling.

“When Lambs Become Lions” will next play at the Sheffield DocFest on June 8th at noon at the Bertha Dochouse Showroom Cinema and June 10th at 7:15 pm at the Curzon Cinema.