Welcome to the Oldest House

After the intro sequence, go through the body scanners to your right. Look on top of the X-Ray machine for the collectible, Prohibited Items Reminder.

Head upstairs and go through the door on the left. Examine the green folder on the desk. Turn around and look on top of the filing cabinet for Bureau Expenditures.

Back out in the hallway, run to the end and turn right. Make your way to the open office at the end. Look on the corner desk for Security Order.

Leave this office and turn left. You will find the walls have shifted, blocking your path back. Press forward and duck into another office on your left where you will find R4 Reports Reminder on a table.

Follow the hallway until you meet Ahti, who directs you to an elevator. Ignore the cupboard to the left of Ahti and continue to the stairs and go down. You will find yourself back in the main lobby. Access the office that wasn't there previously and look on a sideboard for Visitor Evaluations.

Retrace your steps, use the lift, and follow the signs to the Director's Office. Go into the Security Room on the left to find Approved Terminology Reminder on top of a filing cabinet. The level 1 door across the way cannot be opened yet.

Continue forwards, ignoring the two open offices on either side. When the area opens up, look on a filing cabinet to your left for Trench: Do Not Disturb.

Go through the double doors at the end to find the director. Pick up the gun for a scene, after which you will find yourself on the Astral Plane.

Head forward, drop down, and leap across a gap. Clamber up to the next platform. An enemy will appear; use a melee attack to destroy it. Look up to see the Service Weapon hovering above a platform. Climb up and grab it, unlocking the Choose to be Chosen trophy.

Go forward and shoot the two enemies below. Drop down and fight off several more enemies. Destroyed enemies leave behind blue Health Elements that will restore your health. Use the white rope to return to the material world.

Leave the Director's Office for another scene. You will have to kill three Hiss Guards. You will have acquired new collectibles: Director Trench Photograph, Service Weapon, and Objects of Power. Killing the enemies will also give you your first piece of Hiss Research, Hiss Guards. Approach the area where you killed the guards to acquire 300 Source.

Follow the red carpet left and then right again towards Executive Affairs. You will find yourself in a firefight against several waves of guards. Use cover (press the cover button to crouch behind walls or objects) to ensure that you're not caught in crossfire and take them out with your gun.

From the sign, go right. Ignore the first door on your right which leads to a toilet. Go into the next office along where you'll find Executive Meeting Minutes among the papers on the floor. Continue to the end to a meeting room where you'll find a tape recorder with FBC Reminder: Building Shifts.

Go past the Central Executive sign and turn right into the open office area. Go to the end to find Dinner Reservations on a filing cabinet.

Backtrack a short way to find the door to a Shelter. Open it and go inside. On the toilet cistern is a collectible, Marshall: AWE Investigations. There is also a loot container.

Leave the room and continue towards Central Executive. Look in the office on the right to find Urban Legends on top of a cupboard.

Head forward to the landing overlooking the red room. If you shoot one of the figures dangling from the ceiling, you can fight some of the enemies below from up here. They will throw grenades at you; backtrack quickly if that happens. When there are no enemies left, jump down. You will have to face off against another standard grunt and a Hiss Ranger.