The room to your initial left contains [25 PARTS] inside a locker, as well as a Workbench. In the hall, the cupboard next to the entrance of the meeting room contains [(1/2) BLADES], [5 PARTS] and [(1/4) EXPLOSIVE]. The meeting room itself contains [(1/4) BLADES] and [5 SKILL PILLS]. Before you head through the closed door across the meeting room, go to the end of the hall and search the room to the left to find [10 PARTS] inside a locker. The room across the hall is locked and requires a Shiv to open. It houses a [TOOL (LEVEL 4)], the [MOLOTOV: DEPLOYMENT (TRAINING MANUAL)] (which increases the radius by 2x in total), [4 HANDGUN AMMO], [20 FLAMETHROWER FUEL], a [RAG], [50 PARTS], and [10 + 5 SKILL PILLS].
Move through the closed door halfway down the hall and proceed to the stairs, but first read the sheet of paper on the crates Ellie will start to search. After this, head upstairs and open the door to the left to enter a hall. You can find an [OFFICE RECORDER] (which you can play) in the room to the immediate left, and [5 SKILL PILLS] in some drawers in the adjacent room. The next houses [4 PARTS] in a drawer, and the desk in the hall contains [2 EL DIABLO AMMO] and some [BINDING].
You can find a further [5 PARTS] in the desk up ahead. Search the last rooms to your left to find [10 SKILL PILLS], a [HEALTH BAR], [2 REVOLVER AMMO] and [10 PARTS], then move towards the doorway that reads 'exit'. At the end of this room you can find the [FUNGAL X-RAYS]; head through the door in the corner to continue. The next room contains a [LAB RECORDER] on one of the tables. Search the cabinet on the right side of this room to find a [FIREFLY PENDANT (SADIE PEARLE HICKMAN - 231)]. The next office contains [5 PARTS], [(1/2) ALCOHOL], [(3/4) RAG] and [(1/2) EXPLOSIVE]. Enter the last room to trigger a scene. This adds the [FIREFLY'S RECORDER] to your inventory; it can be accessed and listened to via the menu.
After this you'll have to make you way back outside, but several hunters have entered the building, so you must fight your way through them. The best weapon of choice here is a combination of the Hand Axe (dropped by many of your foes) combined with the El Diablo; however, you'll want to make every shot count considering it's clip size and scarceness of ammunition. The Shotgun also works well up close. When you reach the hall of the first floor, a scene will play. After this, you'll still have to kill a few hunters, but the path is rather linear.
Some stuff in a cupboard in the room with the OFFICE RECORDER