It is Carla (Claire van der Boom) who finds the bag in The Square, which has been poorly hidden in her attic crawlspace by her shady, wanna-be gangster husband Smithy (Anthony Hayes). Claire has been cheating on Smithy with her neighbor Ray (David Roberts) for an unspecified amount of time, and once she discovers the money, she sees a way out of her marriage. She shows Ray the cash, and suggests that they take it, then burn her house down while nobody is home, covering up the theft and giving them the means to run away together.

David is hesitant, partially because he's secretly set up a kickback deal that will get him $40,000 of his own escape dough, but mostly because he realizes that someone will come looking for them. In retaliation, Claire stops sleeping with him, and after a few days, David caves. This, of course, is the domino that sets everything in motion, and soon innocent bystanders are being swallowed up, including a pair of small-time crooks named Billy and Wendy (Joel Edgerton and Lisa Bailey), a weaselly repairman named Leonard, and one of Ray's construction workers named Jake (Peter Phelps). Meanwhile, Smithy starts making his own dangerous assumptions about what's going on, and Ray starts receiving cards in the mail claiming to know all of his secrets, and demanding cash in return.

The Square is the brainchild of brothers Joel Edgerton (who, in addition to his role as Billy, came up with the idea and wrote the screenplay with Matthew Dabner) and Nash Edgerton (who directs), and it's worth criticizing these guys about the role that women play in their movie. Carla pushes Ray to steal the money and sets everything in motion. Wendy is unable to act at a pivotal moment and chooses to lie about it, which takes things to the next level. There's also Ray's wife Martha (Lucy Bell), who doesn't act at all, despite some evidence of her husband's dirty deeds (although I have my suspicions that she might have been the final beat in the original treatment, which was reportedly scaled back for fear of seeming unrealistic). The film's major weak link is that none of these characters are fleshed out beyond their basic plot purpose in the movie, and it's a bit distracting.

However, The Square is an undeniable tension generator, gleefully upping the ante for Ray at every opportunity, in ways that seem insurmountable from every angle. Both the script and direction conjure up the cold, clammy sweat of dread over and over again with a shocking amount of ease. In particular, it's impressive how the Edgertons have put together a film that releases bits (but not all) of the tension in carefully-timed beats throughout the running time rather than mounting towards an all-or-nothing ending. Not only is the technique thrilling in and of itself, and a relief to see a movie that doesn't bank everything on the big twist, but it underlines how much control both Edgertons have over the audience's state of mind. It's skillful enough that the viewer can almost overlook the fact that some of these moments are a tad predictable -- they're executed so well, it barely matters.

For awhile, the film had a 100% rating on Rotten Tomatoes, and the trailer features quotes drawing comparisons to Body Heat and Blood Simple. However, while The Square is unquestionably, undeniably "good", even "very good", whether or not it's "great" is questionable. This is the pair's debut feature, and the film is preceeded by one of their numerous short films. The short, "Spider", is more of the same: excellent tension, a pitch-black sense of humor, and a handful of little things stopping it just short of perfection. These guys have their craft and timing down, which so many movies lack. When they master the surface elements, then they'll become unstoppable.