Humdrum suburban couple Jeff (Zach Galifianakis) and Karen Gaffney (Isla Fisher) have just sent their kids away to summer camp, giving them plenty of time to become obsessed with the arrival of new neighbors to their cul-de-sac outside of Atlanta. The picture-perfect new couple on the block are Tim (Jon Hamm) and Natalie Jones (Gal Gadot), a world-travelling socialite duo. But something seems off about their spotless appearance, and Karen commits herself to finding out what their true motives are. So while Jeff develops a man crush on Tim as the vastly different pair bond at an underground snake restaurant and an indoor skydiving facility, Karen takes it upon herself to follow Natalie into a lingerie-store changing room in order to smoke out the truth about their neighbors.
Soon enough, Karen's suspicions are confirmed: Tim and Natalie are actually government operatives working to catch a shady employee at Jeff's workplace (he's the bumbling HR man at a huge aerospace defense firm). With their cover blown and the clock ticking, the spies decide to recruit Jeff and Karen for their plot to unmask the criminal at the company.
The setup (about the first half of the flick) is at times a joyless undertaking, as screenwriter Michael LeSieur employs some heavy-handed foreshadowing and familiar buddy-comedy constructs. But when the action kicks into gear and the Gaffneys become central to the Joneses' espionage plans, the film feel leaner and better paced. Director Greg Mottola (Superbad, Adventureland) makes sure to keep the plot fairly straightforward and fluid, allowing moviegoers to focus solely on the talented cast's misadventures. The central concept is admittedly silly, but Mottola knows how to emphasize his best assets.
Speaking of which, the foursome seem like they're having fun with these fairly ordinary characters. Galifianakis deftly tones down his trademark ridiculousness with a subtler, more neurotic approach. Fisher's role here is a far cry from the sexual dynamo she played so many years ago in Wedding Crashers, but she believably pulls off the part of a curious, stifled housewife. Gadot fills the "sexy foreigner" stereotype with some unexpected humor and attitude, making a convincing case for her career outside of the Wonder Woman universe. And at this point, it's safe to assume that Hamm will succeed in just about any role he takes.
Action comedies about a dull couple's life getting turned upside down (see also: 2010's Date Night) are a film subgenre of variable quality, yet this by-the-numbers effort is thankfully redeemed by its clashing pair of lead twosomes. Harmlessly funny, albeit immediately forgettable, the only surprise about Keeping Up With the Joneses is that it didn't get a summertime theatrical release.