Fans are preparing for the release of the next installment in the Halo series this holiday season, and one of the most significant changes to come to the game is the introduction of Spartan Ops. This takes the co-op gameplay into its own adventure, with cinematic and episodic editions that weave together bits of the UNSC Infinity's story.

During its keynote at E3 2012, Microsoft revealed more information on the long-awaited chapter in the Halo series. This is the first game in the franchise that will not be developed by Bungie, and is said to take a darker turn from the rest of the series. The trailer for Halo 4 launched Microsoft's press conference on Sunday, and features Master Chief navigating through a jungle to pursue a wrecked battleship. Covenant forces then appear on to the scene before quickly passing by, as a giant orb hovers over Master Chief emitting rays of red light. It's clear that these new enemies are not part of the Covenant or the Flood.

It looks like the new Halo game will focus on artificial enemies directly connected to the Forerunners, the creators of the Halos, writes Will Greenwald of PCMag.

The trailer ends with an ominous voice saying the words: I have long awaited for this day, Reclaimer.

This backdrop sets the scene for Halo 4, but there's more than just the cinematic trailer to entice fans. A new compilation showcasing the Spartan Ops gameplay is also available, as The Verge has published along with their E3 2012 coverage. The Spartan Ops mode looks similar to the co-op seen in Halo, but with new enemies, visual upgrades and other additions.

Spartan Ops. The story of the UNSC Infinity intersects with the 'Halo 4' campaign, then continues on in a brand-new, story driven experience known as Spartan Ops, reads the description, according to CVG. A first of its kind and exciting new addition to the 'Halo' franchise, Spartan Ops is an episodic adventure that blends immersive storytelling, high-quality cinematics, and action packed gameplay to deliver an unprecedented serialized experience.

Halo 4 has a release date of Nov. 6, which means that it will be competing against other highly anticipated titles this holiday season. Call of Duty: Black Ops 2 will also be launching that month, and Assassin's Creed 3 will debut just days before on Oct. 30.

The Halo franchise has evolved with the Xbox console itself, and is closely tied with Microsoft's ventures into the video game industry.

If we lose our way with 'Halo,' we lose our way with Xbox, Microsoft Games Studios Vice President Phil Spencer told the Official Xbox Magazine last August.

Be sure to check out the teaser video below for Halo 4: Spartan Ops if you haven't already done so.