It might come as a relief, I guess, when you reach the bloody end of Hafsteinn Gunnar Sigurðsson's slow-boil neighbor-versus-neighbor comedy-gone-wrong Under the Tree and realize oh, good, it's not just America's well-to-do white retirees who have lost their damn minds. Sigurðsson's film concerns, among its twin dysfunction plots, two pairs of suburbanites living in what any reasonable person might assume is bliss: elegant, comfortable, architecturally progressive bungalows in a wooded suburb of Reykjavík, Iceland. But it's the fate and function of big-screen suburbia to be exposed as a hotbed of some vice or another.
Turns out, everyone's deeply suspicious and resentful of everyone else. So much so that, in just 89 minutes, Sigurðsson builds from one husband requesting that the other prune a backyard tree to an eruption of vicious violence. The first scenes are hilarious, all sharp surprises and adeptly staged physical comedy. But then the story turns, the way that milk does, curdling into tragedy. You might find the concoction unpalatable; I laughed and cringed and caught myself once in a while holding my breath, dreading what was next.
It's the kind of movie where, after you smile at a housecat, you immediately start bracing for its possible demise. Kitty goes missing, of course, as tensions escalate between the families. But Sigurðsson maintains exquisite control of our expectations, goosing and dashing them. His characters, like his script, go big early, before you might expect them to, speaking terrible truths or dire calumnies. Then they surprise again, in the later scenes, by exhibiting occasional wisdom and tenderness. Or not. The performances are convincing, each actor committed to a gently heightened naturalism no matter how outlandish the film's reality gets.