As promised, four-player online co-op is here for the PlayStation 3 and PC versions of Warhammer: 40.000: Space Marine, with the Xbox 360 version following soon after. And so the enemy of my enemy becomes my friend.

"Exterminatus," the late-addition cooperative mode for Warhammer 40,000: Space Marine, will release Oct. 25, publisher THQ said today. It had originally been scheduled for an "early October" release.