The Historian achievement is obtained by finding all ten of the Hanwell Mental Institute historical files. These are the files that are labelled with a number, and detail the history and development of the Institute. These files are completely optional, and provide only flavor text for the narrative. HOWEVER, one of these files IS missable, because of story progression.

This guide will contain spoilers, so avoid reading if you do not want spoilers. I will be listing these files in the order that they appear in the "Achievements" tab in the Record Book. This is probably not the order that you will find them in-game naturally.

The first file in in the Meeting Room, which is the room with the psychology books you need to progress at 8 AM. It is on the table on the right of the room.

The second file is in the Cafeteria, which you can enter after you calm Samson. It is on the lunch table in the back of the room, on the right. It is next to the door that leads to the North hallway.

The third file is in the Director's room. It is tucked inside of the drawers on the right-hand side of his desk.

The fourth file is in Hawthorne's Office. It is sitting on top of a book on his fireplace.

The fifth file is in the Laboratory. It is in the large cabinet by the far door. There are drawers at the bottom of it. It is hiding inside the drawer.

The sixth file is in Ebersbacher's Office. It is in one of the tall filing cabinets. It is the cabinet closest by the door, NOT the cabinet with the code-lock.

The seventh file is in the basement, in the room with the mine-cart and boarded up wall. It is on the same table that you took the wire-cutters off of earlier, but you have to go to the other side to see this file. Stand by the pickaxe and look at the table, and you will be able to grab it.

The eighth file is in Operating Room B. It is sitting on an overturned cabinet on the far left of the room.

The ninth file is in the Laundry room. It is on a table next to the door to the Yard.

File 10 is the only collectable in the entire game that can be missed permanently. Make sure to collect file ten as soon as possible. During the chase sequence on the 3rd floor, you will enter an empty room. It is the room in between the room that looks like a storage closet, and the chapel; This means that it is the room that you must trap Samson in to progress. The file is in the top right of the room, next to the chain hanging from the ceiling. You are in no time danger, because Samson will not move into the next room until you leave it.

HOWEVER, you cannot collect this file if you have already trapped Samson in the room. As soon as you block one door, this file is permanently missable. You will have to reload a previous save to collect it.