IF YOU HAVE WATCHED THE FIRST STRIKE MULTIPLAYER PREVIEW THEN YOU MIGHT HAVE SEEN PART OF WHAT IM TALKING ABOUT. IF YOU GO TO THE DOUBLE TAP MACHINE AND LOOK OUT OF THE MAP FROM WHERE THE ZOMBIES COME THROUGH THEN YOU CAN SEE PART OF THE MAP OF BERLIN WALL INCLUDING THE TOWER WITH THE AUTOMATIC TURRETS, ALSO THE BEWARE OF THE SIX THAT IS WRITTEN ON THE WALL IN THE FIRST ROOM YOU START IN, I BELIEVE THIS COULD BE ABOUT THE ZOMBIE MAPS, BECAUSE ONCE ALL THE MAP PACKS HAVE BEEN RELEASED THERE WILL BE SIX MAP PACKS. I COULD BE WRONG ABOUT THE BEWARE OF THE SIX THEORY BUT ITS JUST A GUESS SO I HOPE THIS HELPED 8)