The combination to open the safe is random each playthrough, and can be found in a note in the cash register by the front. You can find this bonecharm in the Winslow Safe Company giant safe on the main floor. The key to the room is in the room to the right with an Overseer nearby (as well as an open window). Near the top of the Overseer building is a locked Interrogation Room. The civilians listening to the Overseers outside won't care if you steal the stuff, so Blink or Far Reach behind the Overseers and slowly creep up onto the tables behind them to take the goods. Outside the Overseer building is a bonecharm next to a Rune. The bonecharm is on the corpse near the Bloodflies. You can Blink/Far Reach across rooftops from the Overseer building to a roof with a dead body on it. The infested building behind the Black Market has a bonecharm on the second floor, can be picked up once you destroy the nest inside. A bonecharm is on the floor of the second story building. To the right of the Wall of Light is an apartment before the canal area that's being raided by Overseers. There is a total of six bonecharms to find on this mission.
