Unknown Caller

Walkthrough for Control's Unknown Caller mission. Guide to navigating the Communications Department, finding collectibles, and cleansing the Object of Power.

Walkthrough:

1. Leave the Board Room, turn right towards the Cafeteria. Loot a container and ignore the Level 1 Security Room door.
2. Deal with Hiss Guards outside the office, loot the container, and find Travel Costs on filing cabinets.
3. Go downstairs towards the Cafeteria, avoiding damage down the right corridor.
4. Defeat five Hiss Guards in the Cafeteria area.
5. Climb onto the bannister near the stairs, scramble up to a ledge, and grab a loot container.
6. From the stairs, turn left to find a Shelter. Find the Havana Summary case file on the seats. The Shelter is blocked by Mold.
7. Return to the Cafeteria and head towards the other staircase.
8. In the ladies' toilet, find Unstable Area Notice on the floor. The gents' toilet has a loot container.
9. Proceed through the doors towards Dead Letters.
10. Go left to find Machine God on the floor.
11. Across the way, shoot one of the three floating Hiss Guards to initiate combat.
12. After defeating them, head down the stairs, turn around, and go underneath to find a loot container and Singing Fish.
13. In the office on the right, find Trench: Dead Letter Approval. The office on the left has a loot container.
14. Go down the stairs here to trigger more guards, including one with a shield. Defeating it unlocks the Hiss Barrier research.
15. Head up the stairs opposite. Before cleansing the Control Point, enter the nearby office and interact with the TV to learn about the Floppy Disk.
16. Cleanse the Control Point.
17. Go back downstairs. The realignment has made two more offices accessible. The one on the right has Book Club: Penny on a filing cabinet and a TV with Missing Momma. The office on the other side has Dead Presidents on a filing cabinet.
18. Return upstairs and go through the door towards the Communications Dept.
19. Go up the stairs and claim a loot container at the top.
20. Go back downstairs and continue to see a man run through the