This pleasurably sadistic thriller by Australian stunt men brothers Joel and Nash Edgerton could scare straight any philandering spouse. (Too bad it’s a few months too late for today’s tabloid soon-to-be ex-husbands.) A married man (David Roberts) is in love with a hairdresser (Claire van der Boom) whose live-in-boyfriend (Anthony Hayes) has a suitcase of illegal money and a serious temper. She demands they take the cash and flee. But his foolproof plan goes foul when the thug he hires to cover their tracks (Joel himself) accidentally creates a perfect storm of accusatory fingers and savage vengeance. Then the anonymous blackmail arrives. It’s no fun to watch the lovers panic as the noose tightens around the necks—but boy does it feel great. With its cast of Aussie unknowns and a small town suburban setting, the flick has an it-could-happen-to-you vérité that has us squirming in empathy. It’s relentless, shunning even a second of comic relief. And the moral can pivot on a dime: is this a karmic noir about consequences, or a nihilistic warning that even a simple scheme can’t be controlled? Either way, it’s a great calling card for the duo who have packed YouTube with a fleet of wicked shorts (here, The Square will screen with Spider, their memorable nine-minute nasty). And if it gets under your skin, dig out 2008′s Shotgun Stories, a stateside drama about warring half-brothers that has the same glum fascination about how small mistakes become big disasters.