It’s not a national border but one far more basic to which the title of Ali Abbassi’s genre-bending film refers. One hesitates to be too specific about the lines that are being crossed here, but suffice it to say that they are no less fundamental than the one dividing the characters in another adaptation of a tale by John Ajvide Lindqvist, Tomas Alfredson’s “Let the Right One In” (2008).

The protagonist in this case is Tina (Eva Melander, her face disfigured by prosthetics and a mask), a Swedish customs officer with such an acute sense of smell that she can detect not only drugs and alcohol being transported by travelers, but the carriers’ emotional states, which can clue her in to possible nefarious activity on their part. In fact, she detects a computer chip inside the phone of one man that turns out to contain files of child pornography, and she’s recruited by the police to help them track down his confederates.

Tina lives in a remote cabin deep in the forest, where she communes with animals on long walks. She has a “significant other”—a shaggy fellow named Roland (Jörgen Thorsson) who raises ferocious show dogs, and regularly visits her father (Sten Ljunggren), who’s in a rest home suffering from dementia.

Still, she seems lonely and isolated until she encounters a strange fellow named Vore (Eero Milonoff, wearing makeup similar to Melander’s), whose bag she checks when he happens by her station. She finds some curious items, like jars of insects, but nothing like what her colleague discovers when he strip searches Vore for a thorough examination.

Tina regrets putting Vore through all this trouble, and after apologizing offers him the use of her guest house. Roland has serious misgivings, but Vore moves in, and he and Tina develop an ever closer rapport. Vore will eventually reveal the secrets of Tina’s childhood, which she will compel her father to confirm; but he has secrets of his own, which dovetail not only with the police investigation of the pedophile ring but with a subplot about Tina’s neighbors, who have a newborn girl.

“Border” is unquestionably one of the stranger romances one is likely to encounter this year, but it’s a weirdly satisfying one that also raises questions about what it means to be human. Rich in folkloric and quasi-supernatural elements, it fascinates and surprises in equal measure, although the languid pacing set by Abbassi and editors Olivia Neergaard-Holm and Anders Skov requires some patience. The combination of Frida Hoas’ production design and Nadim Carlsen’s cinematography gives the images an appropriately grubby, lived-in look that nonetheless has a touch of the fantastic, and the score by Christoffer Berg and Martin Dirkov is subtle and unobtrusive.

The highest praise is due the large makeup and effects teams, but their work would mean little if Melander and Milonoff weren’t able to invest Tina and Vore with the depth and shading that lies beneath their surface appearance. Their performances are marked by subtleties of expression and movement that are at times almost unnoticeable but disclose the characters’ emotional underpinnings.

There’s little doubt that genre aficionados will appreciate “Border” for its imagination and craft, and even those who find it absurd should applaud its audacity. It’s not for everyone, to be sure, but its uniqueness is compelling.