A $100 million movie isn’t cool. You know what’s cool? A $500 million videogame.

At least that’s what David Fincher, the acclaimed director of The Social Network, seems to think. According to two Microsoft executives who have spoken exclusively to The Daily Beast, the auteur’s next big project isn’t a movie, or even a trailer for one. Instead, Fincher has produced a mysterious, two-minute teaser for a videogame: Halo 4, the long-awaited sequel to Xbox’s blockbuster action trilogy.

Fincher is a Halo fan. But it’s also a savvy move. The game may prove the biggest entertainment launch of 2012—in any medium.

Other stars have taken note. Conan O’Brien and Andy Richter are slated to voice two of the game’s minor characters. The franchise is even using the presidential race as a marketing opportunity. If you use your Xbox to watch three of the four debates, Halo 4 will reward your civic zeal with shiny “warrior armor”—so you can eviscerate aliens, patriotically.

When Fincher’s trailer premieres on Late Night With Jimmy Fallon on Oct. 18, it will mark something of a renaissance for console gaming. As analysts presage the rise of mobile gaming and fall of bulky consoles, Microsoft is quietly planning a huge rollout for its most important launch of the year. It might just be gaming’s biggest coming-out party.

Music and movies tend to get a lot more Wall Street attention than videogames. But in 2007, Halo 3 made $300 million in its opening week alone—that’s more than The Avengers’ first week, and more than the Social Network’s total gross. The first Halo was the first Xbox killer app: a sci-fi space opera from a little-known studio, Bungie, which Microsoft had snapped up in 2000. At the time, the gaming press speculated that the buy might have had something to do with color scheme: the green hue of Master Chief’s suit meshed well with the new console’s own aesthetic.

Six games later, the franchise has made $3 billion on 43 million sales. There are Halo novels, miniseries, and reams of florid fan-fiction. “Halo has transcended a traditional videogame,” says Rob Matthews, head of global consumer marketing for Microsoft’s interactive-entertainment division. “It’s a major part of pop culture.”

Microsoft thinks that gaming has finally climbed out of the parental basement—and is risking a lot to keep it there. This year the company posted its first-ever quarterly loss. And as the Xbox ages, its sales have slowed. Xbox holds about half of the console gaming market, which saw declining sales in 2011. Although Microsoft’s revenue hit all-time highs this year, other sectors of its business have faltered—most notably, the bleeding Bing division. Halo 4 has the potential to start the next fiscal year with a plasma bang.

To make matters even more interesting, the game will be the first in the series developed exclusively by Microsoft’s own team, 343 Industries. Bungie split amicably from Microsoft after the launch of Halo 3, with the larger company retaining all intellectual property. And it plans to put those assets to work in an all-out, international, multimillion-dollar marketing blitz.

You’ll be able to buy Halo-branded Doritos with your Halo-partnered American Express card, and wash them down with a proprietary, Halo-branded Mountain Dew concoction. Moreover, the game’s brand partnership with PepsiCo is the largest ever for the videogame industry, said Bryan Koski, head of Xbox Global Marketing for Microsoft. The company is producing its own live-action miniseries, Halo 4: Forward Unto Dawn, which it plans to stream for free. And though the details are hazy, Microsoft plans to take over “a central European principality” for a day, and fill it with re-created set pieces from the game. The soundtrack will be composed by Neil Davidge, the man behind Massive Attack, and remixed by James Iha, former Smashing Pumpkins guitarist. And for television ads, rather than plastering generic spots across the networks—or even the Fincher preview—Halo 4 will be developing custom segments to fit in with specific shows: FOX’s The Fringe and FX’s Sons of Anarchy, as well as slots on Comedy Central and ESPN.com. When the game finally launches on Nov. 6, it will hit 7,000 American stores simultaneously, with glitzy events from New York to Berlin. Matthews waxes poetic: “Marketing is about romancing all of that,” he says. “We are reinventing the way videogames are made and marketed.”

Part of the romantic—and highly expensive—marketing push is a product of necessity. The consoles are showing their age, and the old-school joystick and shoot play model is ceding ground to motion-capture, not to mention mobile pick up and play. But until the next generation rolls around, Microsoft’s biggest, non-Windows brand still has more selling power than almost any other gaming franchise. And so, expect to see Master Chief, Halo’s super-soldier protagonist, almost everywhere, aiming his high-caliber carbine rifle right between the Angry Birds’ eyes. He’ll also rain fire on Nintendo and Sony, whose own consoles are fighting for elbow room in a weakening retail gaming market. As Christmas bells ring, the retail stakes couldn’t be higher.