The fan-favorite co-op zombies mode is back in this year's Call of Duty: Black Ops II and the first trailer for it makes it look... ambitious.

First of all, there's not a whiff of hint in this trailer that Blops II's Zombies mode has any connection to the sequel's near-future-America-under-high-tech-attack story. Instead, it looks like, well... it looks like a game of co-op civilians-vs-zombies, set in some sort of middle-America wasteland. There even appears to be some sort of world map, though it's not clear if that's just for presentation purposes in the trailer or if it is its own thing.

Mark Lamia, whose Black Ops studio Treyarch has been putting zombies in their Call of Duty games told Polygon that the zombie campaign is called Tranzit and is spread across a "massive" open world. Players travel from zone to zone in a fortified bus.

The new game will also include a humans vs. humans vs. zombies (that's eight human players!) mode called Grief, which combines competitive multiplayer with fights against the zombies. The last team standing wins, Polygon reports.

It certainly seems that all this Zombies stuff could have been its own standalone game. The fact that this is all being added to the already-impressive Black Ops II—on top of its branching campaign and extensive competitive multiplayer modes—is, well... it's a lot of game.

Black Ops II will be out for Xbox 360, PS3, Wii U, and PC on November 13.