With the map comes another backstory. So here it is. While during his 2009 campaign, now United States President Barack Obama and his vice president Joe Biden go to the pope to help increase their chances with winning by getting the pope and thus the Lord's grace. Unbeknownst to them fellow candidate John Mccain is doing the same thing. The Pope however is not the real pope. Rather he is a new project by Group 935 to see if Element 115 can be used to clone. Upon the 2 candidate's (and vice president's) arrival and reaching the meeting room the horde starts.
This time getting downed means something! Upon getting downed you will go into a normal downed position. As time goes on and you begin to die you will look more zombie like and less human. The Syrine is now a reversal concoction that reverses the infection in your system. If you die you will come up as a zombie. While having no control over your movement (forces you to follow teamates) you can hit and down ex teamates whenever or fellow zombies. To be killed you can't be dismembered. Upon the start of a new round you will be human again and say something about how being one of them was terrible (they are canically given the serumn. While a zombie you can hear Samantha ordering you giving hints on when to hit and other stuff related to what the humans are doing.