The A.R.C. is built around a octagon where each of the six levels have 4 wings. The player goes through the core of few times through out the game.
Chapter One: Welcome to UnderhellEdit
Jake first goes through the core when first arriving at the A.R.C, a helicopter carrying Jake brought him down to Level 0 where he was taken to the prison blocks.
Jake later visits the core after the infection outbreak, due to the lack of power, the ceiling could not be seen through the darkness, Jake went down to maintenance where he restarted the power to the core, making it possible for the core's doors to be opened without having to cut power to another wing.
While fixing the power, a helicopter landed at the Core's helipad, due to the roof being closed and all but one of the survivors not being able to fly a helicopter, using the vehicle for escape was out of the question, the helicopter stayed at the core until Jake reached floor 2.
As an effect of getting the cypher codes, every door on floor 1 was accessible to Jake.
After reaching floor 2, guards had taken over most of the facility and a new squad of guards were being unloaded off the helicopter, after being unloaded, the helicopter began to rise and the core's roof opened to let it free.The cypher codes also changed, meaning that Jake could now only open pre-opened doors at the core.
Close to the end, a jet was called in to deal with the situation at the A.R.C, the harrier attempted to gun down everyone who tried to access the core causing the group to find shelter behind the bullet proof glass, after escaping the core for the last time, the jet attempted to crash into the group, but failed making it crash into the level 0 maintenance access.
The core appears briefly at the end in a flash back
- There is a card hidden inside the helicopter
- The core has similar architecture to that of a missile silo, possibly explaining the need for bullet-proof glass