Just when you think Burger King can't top the crowning glory of last year's Whopper Detour campaign promoting its mobile app, it pulls off a battle royal from within its chief rival's own stores. 

Last year, BK won countless awards for geo-targeting offers for a 1-cent Whopper to customers who come within 800 feet of a McDonald's (see the success story below). But BK Germany may have upped the ante—again. 

In a cross promotion celebrating the release of "It Chapter Two," Burger King is using advertising on Facebook and Twitter to invite consumers to download its mobile app and scan a review of "It" within a movie magazine McDonald's distributes in-store.

According to The Drum, when consumers download the app, they're able to play an augmented reality-enabled mobile game that displays a "flee and run" route to the nearest BK. If they make it there within a certain amount of time, they're able to buy a Whopper for just one cent. 

It's just the latest in the kind of inventive campaigns that helped BK clean up at this year's Cannes Lions Advertising Festival—and at the cash register. And in truth, BK's unorthodox philosophy about marketing has been on display as far back as its work with CPB Group.

With this brilliantly devious cross-promotion, the QSR might just win "Creative Brand of the Year" for a second year in a row.