After grabbing the Intel from the bloodied room, head to the back of the area and climb up the stairs. A set of double doors will await you at the end. Approach the door, and a zombie will burst through and grab you. You will be caught inside of a crowd of zombies. If you brought along your Shotgun, open fire to tear the enemies to pieces. If you don’t have a Shotgun, the best you can do is distance yourself from the undead a little bit and hope that they don’t have the chance to infect you. Dive out of the crowd towards the back of the room, giving yourself a little more space to operate. When you are clear of the crowd of zombies, open fire from the hip at the general level of their heads. You are so close to them, you’re likely to score a series of headshots. If you get infected, don’t hesitate to use the Antiviral Spray that you picked up at the last checkpoint. The more you allow the infection to affect you, the lower your health will be when you return to a normal state.
When all of the zombies are dead, look to the bottom of the steps to find another small group. They will be eating the corpse of another zombie. Gun them all down before they even realize that you are there. Aim for the barrel next to them to cause an explosion, killing them all at once. Head to the lower level and grab the Intel from the shelf. It is also likely that you will find a Green Herb here, dropped by one of the exploded zombies. Proceed to the back of the area and open the door. More zombies will charge at you. Go for headshots and let your team help you mow them down as they come. Walk up the stairs and look to the left to find even more zombies. They will attack you when you reach the top of the steps, so open fire on them before they get the chance to touch you.
Search to the right of the exit to find Intel sitting on the boxes here, then head around to the left and search these boxes to find more Intel. Head through the door on the left side of the area to find a few more zombies. Backpedal out of the room and kill them as they are funneled through the door. Search inside of this room to find an ammo stash and a few alternate primary weapons littering the ground. A Green Herb will also sit inside of this area.