It has the escalating, claustrophobic structure of the darkest farce, but humor doesn’t pile up in “Under the Tree” so much as it bleeds out. In the course of Icelandic writer-director Hafsteinn Gunnar Sigurdsson’s memorably mordant third feature, savage black comedy passes almost imperceptibly into stunned, visceral tragedy — like a laugh turning in the throat and coming out as a choke. Charting an initially familiar battle of across-the-fence attrition between bad neighbors in polite surroundings, Sigurdsson gradually takes petty bourgeois tensions to alien, gasp-worthy extremes; what the film occasionally lacks in human finesse, it makes up for in sheer anything-goes resolve. The bleakness of its blackness might not portend a major crossover hit, but on the strength of both its universality and its singular Scandi irony, “Under the Tree” should spread its branches into international arthouses.
Columbia graduate Sigurdsson’s 2011 debut feature “Either Way” wasn’t widely released beyond the festival circuit, but wound up being comfortably remade by David Gordon Green as “Prince Avalanche” — and it’s not hard to see the director’s latest enjoying similar treatment, given how smoothly its sins-of-suburbia narrative could transfer to a middle-American context. Which is not to say “Under the Tree” wants for cultural or geographical particularity, beginning with the dove-gray northern light that dominates Monika Lenczewska’s deliberately muted widescreen lensing: With a wry eye for trivial detail, Sigurdsson fills in a boxy, tidy, perennially overcast world where even the outdoors seem indoors, and the parking lot of IKEA doubles for one desperate parent as an idyllic picnic spot.
The parent in question is Atli (Steinþór Hróar Steinþórsson), an unremarkable thirtysomething husband and father thrown out on his ear by his wife Agnes (Lára Jóhanna Jónsdóttir) after being caught wet-handed with an old girlfriend’s sex tape. Her calm, abrupt decision to cut him from her life and that of their young daughter sends Atli into a fevered spiral of stalking, though their messy, hostile separation is practically civil compared to the film’s other driving dispute, as Atli’s retired parents — into whose trim modern identikit house their son is forced to move — go to war with their younger, somewhat hipper neighbors Konrad (Þorsteinn Bachmann) and Eybjorg (Selma Björnsdóttir).
Sigurdsson and co-writer Huldar Breiðfjörð’s Chablis-dry script deftly staggers conflict not just across domestic walls, but between them, with points of argument ranging from patently absurd to distinctly raw. Atli’s father Baldvin (Sigurður Sigurjónsson, quietly excellent) is mild-mannered to a point; his mother Inga (Edda Björgvinsdóttir), however, has long dispensed with niceties even to her nearest and dearest, corroded as she is by mourning for an absent second son. Unhinged grief pulls her into arguments with anyone, with newish trophy wife Eybjorg her most persistent opponent — and the vast, venerable tree in Inga’s backyard their most regular bone of contention.
Such towering natural features are rare in an area of manicured lawns and sharp-cornered patios, and the film and Inga alike treat the tree as an old-school emblem of tradition and security; to Eybjorg, however, it’s merely a large, unwanted shadow on her year-round sunbathing space. Foliage isn’t the only thing under threat in an ugly clash between old and new worlds: Family members, material possessions and pets are all potentially caught in the crossfire, and Sigurdsson watches the extreme fallout with a dispassionate gaze that only amplifies the frequent, galling ugliness of the situation. Given the most flagrantly off-kilter character in the ensemble, Björgvinsdóttir takes much the same approach: Her deep-frozen performance skilfully hovers on the line between catatonic and psychotic, with alternately, sometimes simultaneously, hilarious and horrifying results.
Talented, country-hopping cinematographer Lenczewska (whose diverse recent credits range from “Message to the King” to the new-wave Greek formality of “Park”) opts for about the most washed-out palette available in each frame — a half-erased palette that initially seems limiting but eventually connotes the pervasive extent of the characters’ respective emotional fugs. Daníel Bjarnason’s tart, brittle score makes clear from the outset that this is no cuddly dysfunctional family sitcom, though its yawning silences leave plenty of room for unsettled laughter.