Ningiuq (Madeline Ivalu) and Maniq (Paul-Dylan Ivalu) prepare to leave for their island in the Inuit drama Before Tomorrow. (Alliance Films)

There's a sound right at the beginning of Before Tomorrow that most Canadians will recognize, but that we seldom encounter in movies: it's the delicious crunch of boots on thick, crisp snow. That sound — one you'd never hear in a Hollywood production — represents to me all that's wonderful about the films of Nunavut's Igloolik Isuma Productions. They're so disarmingly authentic that, watching them, you feel as if you're discovering the North onscreen for the first time.

With films like Before Tomorrow we're witnessing the flowering of an indigenous Inuit cinema. It's the most exciting thing to happen in Canadian film this decade.

Isuma has taken that documentary-like realism and enhanced it with superb artistry. In its previous features — Atanarjuat: The Fast Runner (2001) and The Journals of Knud Rasmussen (2006) — and now in this third panel of its historical triptych, we're witnessing the flowering of an indigenous Inuit cinema. It's the most exciting thing to happen in Canadian film this decade.

After the expansive Atanarjuat and the surreal Knud Rasmussen, Before Tomorrow is a much more basic and intimate tale. It's as bare bones as the picked-clean caribou carcasses that figure in its early scenes. Like the best minimalism, though, it says as much in its silences as in its words. By the end, the film has quietly evolved into a heartbreaking story of love at its most elemental.

Before Tomorrow, based on a 1975 novel by Danish author Jørn Riel, is set circa 1840, at the time of the Inuit people's first contact with Europeans. It opens with a flash-forward: those crunching boots we hear belong to Ningiuq (Madeline Piujuq Ivalu), an Inuk elder, and her 12-year-old grandson, Maniq (Paul-Dylan Ivalu), as they trudge through a stark winter landscape toward their makeshift shelter in a cave.

Then we're taken back to the previous summer and an idyllic scene. Ningiuq, Maniq and their family, camped by a sun-dappled lakeside, welcome a group of fellow nomads for a reunion and celebration. As the group feasts and chatters, a jolly patriarch (Tumasie Sivuarapik) describes a recent encounter with some white-skinned strangers. His listeners are amazed as he tells them of the white men's mysterious knives and needles, much sharper than bone, and their magical water, which made them giddy and led them to sleep with the Inuit women. Behind the group's laughter is a foreshadowing of the disaster to come.

At summer's end, Ninguiq prepares to take her family's catch of fish to a distant island, where she will dry them for the long winter. The devoted Maniq insists on coming along, as does Ninguiq's old friend, the dying Kutuujuk (Mary Qulitalik). On the island, Kutuujuk finally succumbs to old age, but Ninguiq is comforted by the presence of her lively grandson, who helps her prepare the catch and proudly harpoons his first seal.

Autumn passes and still no one arrives to bring the pair back to the camp. When Ninguiq and Maniq finally return on their own, they discover the devastating after-effects of the meeting with the white men. Their family gone, the old lady and the boy must fend for themselves as a hard winter sets in and hungry wolves begin to prowl.

Maniq helps his grandmother as they prepare for the coming winter in Before Tomorrow. (Alliance Films)

Before Tomorrow is a collaboration between Isuma and Nunavut's Arnait women's video collective. Actress Ivalu, Marie-Hélène Cousineau and Susan Avingaq – all members of Arnait – wrote the screen adaptation. Cousineau and Ivalu also co-directed the film, which won them the prize for best Canadian first feature at the 2008 Toronto International Film Festival. The pristine cinematography is by Isuma co-founder Norman Cohn, who shot Atanarjuat and Knud Rasmussen, and Félix Lajeunesse.

Like those earlier films, Before Tomorrow blends sophisticated filmmaking with natural acting that's as spare and eloquent as a soapstone carving. Ivalu, who played the indomitable widow Panikpak in Atanarjuat, is the maternal force at the centre of the picture. As the sturdy Ninguiq, she shelters her beloved grandson both literally and metaphorically. She sings to him, tells him stories and keeps him cheerful with talk of another Inuit community, filled with children, which they will seek out when the winter is over. To the spirit of her dead husband, however, she confides the harsh truth of their situation.

Maniq, portrayed by Ivalu's real grandson, has the sweet, open face of a child still several winters away from taking on an adult's responsibilities. Although he is learning to hunt and gather, in his spare time he still plays a little boy's games. His scenes with Ivalu are imbued with tenderness and suggest an uncomplicated love between the two that's as pure as the first snow.

The picture was filmed at different times near the remote Nunavik community of Puvirnituq, providing a panorama of the Arctic seasons. The musical score makes effective use of songs by quirky folk legends Kate and Anna McGarrigle, particularly Why Must We Die?, a tune off their 1996 album Matapedia. Trust the McGarrigles to turn that sombre existential question into a lilting ballad – its insistent chorus has been running in my head for days. In the context of the film, the song's question resonates beyond personal mortality to encompass a people and a way of life. And, like the McGarrigles, filmmakers Cousineau and Ivalu are at once sorrowful and unflinching in their contemplation of the inevitable.

Yet I didn't leave Before Tomorrow feeling sad. After all, it stands as proof that the Inuit culture, threatened by the long winter of European colonization, has not only survived but found a new means of expression in rich, vital films like this one. That's a reason to rejoice.

In Inuktitut, with English subtitles.

Before Tomorrow opens in Montreal, Toronto and Vancouver on March 27.

Martin Morrow writes about the arts for CBCNews.ca.