The Mother's Letter lies on a white armchair behind a door marked with a red X, right beside the blue truck as you enter the area before the hotel in Pittsburgh. The door is locked, so bring a shiv.
Eva writes that the army branded her son a traitor. Furious, she has joined the rebels, been given a gun and a mission, and expects not to survive it.
She buried her son the day she wrote it, apparently killed after joining a protest. Joel remarks that with that thinking nobody wins.
The Stash Note found close by mentions supplies hidden behind a red X at the Regal Apartments.
Abandon Zone Note
The Abandon Zone Note sits on the desk in the office at the far left end of the bookstore's first floor in Pittsburgh.
Accretion
Accretion, issue 6 of Savage Starlight, sits on a coffee table in a lounge on the second floor of the Hotel Grand, during the Hotel Lobby section of Pittsburgh.
Ambush Map
The Ambush Map is pinned to the wall of the room at the end of the hallway. Leave the stairs in the room with the two dead bodies, follow the corridor to its end and look on the wall.
Applicant Checklist
The Applicant Checklist is under the stairs on the far left of the bookstore's ground floor in Pittsburgh.