The Medium has a number of collectibles for you to unearth. One of those are the Troubled Man’s Notes, which is tied to a secret achievement called An Unknown Outcome. It’s worth 40 Gamerscore, and you have to collect all 18 notes in a single playthrough to unlock it. Here are their locations so you can acquire this achievement as you play.

A Peaceful Place

Find this note after catching up with Sadness outside Thomas’ office. Look in a discarded box on your right before you enter his office to find the note.

To-Do List

Inspect the broken desk in the office. Look down to your right to find it on a shelf.

Getting Stronger

Check in the red room behind the office. Walk around the projector and its desk, and look for the page on the floor.

Fever Dreams

Sadness’ spirit trail will lead you to the Dayroom’s locked entrance. Walk up the steps to your right and walk behind the pillar on your left. The page is on the floor next to it.

Good Old Frank

After you leave the swimming pool’s changing rooms, follow the narrow corridor into a wider one. Before you walk forwards towards some debris at the end of the walkway, look for the page on your right among some foliage.

Dust and Death

After you acquire the bolt cutters and before you open the Dayroom’s entrance, go back on yourself to the hotel lobby. Open the locked gate at the back. Walk towards the pile of tables and chairs to grab the page.

Something Broken

After the cutscene with Sadness on the swing, head into the garage at the end of the path and walk to a worktop at the far end. Inspect a suitcase to find an Echo, and then look down for the note on a shelf to your right.

Demons

Inside the Red House’s ruins, there is a room blocked by rubble to your right just past the mirror. The note is sitting on the debris.

A Different Kind of Sickness

As you enter the Red House’s basement, walk forward and hang left. Follow the wall towards a desk and some overturned chairs at the back. The note is on the desk.

The Missing Piece

Go back on yourself towards the basement’s entrance. Walk past it to your left until the camera angle changes. Facing the wall, look left for the page on a shelf.

Found a Way

Turn right and walk into the cellar. The page is on the floor at a dead end.

Separation

After you escape The Maw in the bunker’s corridor, look at the desk in the room for the note.

A Relic of the Past

Look on top of the control panel in the water pump station control room.

A Thin Line

Check in the bunker’s fuse room after you electrocute The Maw. From the fuse box, walk down the steps and take the first right. The page is on a metal shelf.

Alone

After you grab the replacement fuse outside of Lily’s room, head inside and grab the note from her desk.

Just Me and Her

Looking at the broken mirror in the bunker’s kitchen, turn right and wait for the camera angle to change. The note is on a table.

Keeping Distance

In Thomas’s study, while you search for the mirror’s pieces, look on the bookshelf on the right wall after you enter.

Business Card

From the book shelf, walk forward a few steps to grab the card from a table.