Her unseen interviewer asks questions that bring Lokita to tears.

It’s not that what the Belgian immigration counselor asks the teenaged girl from Benin about is painful or troubling. Lokita (Joely Mbundu) is lying, and keeping her story straight — about her life, her school and how she found her “persecuted” “sorcerer child” brother and helped him escape with her to Europe — is damned near impossible.

Every wrong answer moves her further away from getting her papers and a fighting chance to start a new life in Europe.

“Tori and Lokita” is a compact, plaintive thriller about the tragic trials of immigrants after they’ve completed the harrowing journey across Africa, after they’ve braved the desperate crossing of the Mediterranean at the hands of mercenary, cutthroat traffickers.

When we meet tweenaged Tori (Pablo Schils), it takes a few minutes to grasp that they aren’t real siblings, but that the Belgian insistence that a simple DNA test will settle the matter won’t settle anything.

Whatever they went through, they are bonded for life.

Sibling Beglian filmmakers Jean-Pierre Dardenne and Luc Dardenne (“Two Days, One Night”) dole out the clues about this relationship in a glimpse here, a detail revealed there.

Tori and Lokita work at a local cafe, singing karaoke to the diners, occasionally dueting “an Italian song we learned when we landed in Sicily.” But after the singing, they’re out making deliveries, and it’s not pizza they’re taking to the club bouncer, the hipsters, college kids and the self-medicating. It’s drugs.

Tori and Lokita live in a halfway house for immigrants, going over their “story” so that they’ll pass that next interrogation, scraping together cash to “send home to (her) Mom.”

But the ruthless African smuggler (Marc Zinga) and his henchwoman (Nadège Ouedraogo) aren’t concerned with their well-being when they demand to know why “you weren’t in church Sunday” (in French with English subtitles). That’s where Firmin collects his payments for getting them from Sicily to Belgium. He and his partner Justine shake Lokita down every chance they get.

The siblings’ chef-boss Betim (Alban Ukaj) rides them hard to make their drug deliveries and limits their take. They’re stopped by cops because they stand out and look like illegal immigrants. They’re not suspected of drug dealing because they’re young siblings traveling together.

But when Tori’s not around, Betim demands sexual favors of Lokita.

With all that, the fear of a DNA test, pressure from “home,” the cost of getting illegal “papers” and clothing them, it’s no wonder that Lokita takes medicine to ward off panic attacks. Sometimes, the medicine doesn’t help.

Tori, a somewhat reckless and impulsive kid, is having to grow up and man-up awfully fast under these conditions. He tries to take on more of the “work” himself and pleads their case to the immigration counselor after Lokita’s broken down in tears.

“She’s my sister! She saved my life!” At least half of that, we know, must be true.

The Dardennes brothers have made stories of Belgium’s underclasses — orphans and immigrants — a speciality. They know what they’re doing as they take this tale and these two simply-written, compellingly-acted characters into even darker places as they explore the extremes these two will go to in order to remain together.

Every action in this Cannes award-winner is motivated if not wholly rational. Every consequence grimly believable and shorn of artifice and melodrama.

And Mbundu and Schils put human children’s faces on the pitfalls of open borders in an era of exploding, climate-and-conflict-driven human migration, and help us understand the desperation behind it. Leaving a bad situation in search of a better one is as human an instinct as clinging to “family,” however it was formed.

Rating: unrated, violence, sexual abuse, drug content

Cast: Pablo Schils, Joely Mbundu, Alban Ukaj, Nadège Ouedraogo and Marc Zinga

Credits: Scripted and directed by Jean-Pierre Dardenne and Luc Dardenne. A Janus release on The Criterion Channel.

Running time: 1:29