It is a zombies game, where 4 characters are the heroes.
They will seek to survive and escape from the city to an infection-free army zone. Each character has a story that will be told while passing the levels. 
The game is cooperative online, where they must gather pieces of the map to escape but also  They will have the help of the army through a radio that they found in a fallen helicopter. 
Advancing in the story, each character will find his goal and defeat zombie bosses along the way.You need to survive to the zombie´s attack and beat them with your friends