Halo 4 will be released holiday 2012, marking the start of an new trilogy for Xbox 360, Microsoft has announced.

The game is in development at Microsoft's internal 343 Industries.

Set in the aftermath of Halo 3, Master Chief returns to confront his own destiny and face an ancient evil that threatens the fate of the entire universe.

A trailer featured Cortana pleading for help from John (Master Chief), seemingly after events of Halo 3 when Master Chief is left in Cryostasis. The Chief awakes and some cool stuff happens.

See for yourself below.

Perhaps more interesting is the wording of the announcement - a trilogy for Xbox 360. Even churning out one game a year that puts us at the back end of 2014, suggesting we won't be seeing the next Xbox platform until 2015 at the earliest.

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