Quick, everyone check your co-op partner. I think we lost a man. A CoG tag has mysteriously shown up at Co-Optimus Headquarters which can only mean one thing, there's a fallen soldier somewhere.
Seriously though, the CoG tag opens up some unique content on a special website, and lucky for you - we have the code that unlocks it.
Head on over to http://gearsofwar.com/lastday and enter this code: 329279-DN5XS-AO
You'll see a little red CoG button at the bottom, this is where you click to access the code screen.
