Like an agent lying low until it's time to rappel through a window, pull a gun and spray mayhem in every direction, The Spy Who Dumped Me stayed in the shadows right up to its release. Last week I caught an ad for the action-comedy on TV. Surprised, I momentarily suspected that what I was seeing was some sort of digital short or parody.

What's this? I wondered. The answer, I discovered two days later, is the breezy, completely bonkers buddy film for which we didn't know we'd been waiting all summer.

Mila Kunis has been on a mission to get a movie like this made. For years, studio after studio passed on her pitch for a spy caper fronted by female leads. Costar after projected costar eventually moved on to other assignments. Planets finally aligned when Kunis, "Saturday Night Live" star Kate McKinnon and director Susanna Fogel (Life Partners) connected with Lionsgate. It didn't hurt, of course, that Kunis' shoestring comedy Bad Moms had just stunned Hollywood by cracking the $100 million mark. Suddenly the plan didn't sound so risky.

Kunis and McKinnon play BFFs Audrey and Morgan, respectively. No sooner do we learn that Audrey's boyfriend, Drew (Justin Theroux), has broken up with her (by text, no less!) than the cad rappels through the window of the LA apartment the women share, pulls a gun and sprays mayhem in every direction. Which is one way to blow your cover as an NPR host.

With sinister forces close on his heels, Drew confesses to working for the Central Intelligence Agency. Seconds before being gunned down, he pleads with Audrey to deliver a top-secret trophy to a contact in Austria the following day. The fate of the world, needless to say, hangs in the balance.

The statuette and its contents are, naturally, only a MacGuffin, an excuse to unleash the pair on an unsuspecting continent. What follows might be described as a mutant hybrid of Taken and National Lampoon's European Vacation as executed by Sam Peckinpah. Fogel, who wrote the screenplay with David Iserson, mixes R-rated yuks with wincingly graphic yucks.

As McKinnon and Kunis hopscotch among Vienna, Prague, Paris, Amsterdam and Berlin playing wannabe double-0s, they gleefully subvert a number of espionage tropes and leave a steeper count of grisly casualties in their wake. For every diarrhea or vagina gag, a dozen Eurotrashy baddies are impaled, blown to bits or dismembered. Yet somehow the movie's lighthearted, screwball vibe never sours. These girls just want to have fun. Even if that occasionally means getting medieval.

This is a spy spoof that isn't all that interested in either spying or spoofing. Rather, Fogel appears to be under orders to drop McKinnon into perilous territory just for the fun of watching her reactions. She's the picture's secret weapon, the most quick-witted, absurdist comic force to hit the big screen since Melissa McCarthy.

The film has a running gag about Edward Snowden having the hots for Morgan. It's a completely out-there premise that, like all the others, McKinnon renders credible and good for a data dump's worth of laughs.

More vitally, the chemistry she shares with her costar comes off as warm as it is whacked-out. Nobody's pretending to reinvent the wheel here. With a plot hinging on the affections of several undercover hunks, this is that rarest of chick-led flicks, one that manages to flunk the Bechdel test with nothing less than flying colors.