Click 
for in instant view of the collectible. Read it, then watch it.
This will not work on Apple mobile iDevices.
Artifact – Military Pamphlet – Story related
Artifact – Boston Q.Z. Map – Story related
Conversation #1 – Located in Chapter 2 in the Quarantine Zone when you get out into the street. You will come across a security checkpoint. Instead of going to the security checkpoint, there will two people you can initiate the conversation with along the right side of the street as you approach the security checkpoint.
Conversation #2 – This is will be a little further on in Chapter 2 after you have collected your gear and made it back to the surface through a building. Follow Tess and she’ll stop just outside and you can start an optional conversation with her.
Firefly Pendant – David Michael Vigil – After moving, and then climbing a ladder, make your way to the back room before taking the stairs down and you’ll find this on a table against the wall.
Artifact – Note To Brother – After you clear the first area where you learn how to use Joel’s hearing, walk up the stairs to the second floor and go to a room on the left.
Firefly Pendant – Ben Glueck – After walking over a plank you will come up to an area with a door that you will go through. In this area, hanging from a tree is this pendant. Shoot it to bring it down.
Artifact – Drafting Notice – In the first camp you come across you will travel through the inside of a bus to come out the other side. In the back of this next area on the ground will be this artifact.
Artifact – Wanted Poster – Just past the previous artifact in the same area, about 20 feet away hanging on the wall next to a fence
Artifact –Warehouse key – This will drop off one of the bad guys that you encounter in or around a building. This will be the second fight after leaving the camp. This can’t be missed.
Artifact – Shipping Manifest – You will encounter a large area with a lot of bad guys when you find Robert. This will be along the railing near the water to the right.
Artifact – Dock Notes – This is in the same large area with a lot of bad guys when you first see Robert. This will be along the right side behind a blue container near the elevated boat.
Firefly Pendant – Philip Liu – The first time you and Ellie are out by yourselves, there will be a few dead bodies in the immediate area. This pendant is near the one leaning up against newspaper dispenser.
Watch full Grounded mode difficulty walkthrough with collectibles
Select a Chapter/Guide
Chapter 2 – Quarantine Zone (note, there are none in Chapter 1)
Chapter 3 – The Outskirts
Chapter 4 – Bill’s Town
Chapter 5 – Pittsburgh
Chapter 6 – The Suburbs
Chapter 7 – Tommy’s Dam
Chapter 8 – The University
Chapter 9 – Lakeside Resort
Chapter 10 – Bus Depot
Chapter 11 & 12 – Firefly Lab and Jackson
All 37 Optional Conversations
All 5 Ellie Joke Conversations
Toolbox Locations
Shiv Doors
Hello Brian I just wanted to let you know that I really found this guide very useful and obviously I wanna thank you for helping me out, also I wanted to ask if there is any way of knowing which conversation you have completed, it seems that either I skipped one or like you pointed out in the beginning of the conversation section the game just didn’t counted one, thanks again man, great work as usual, I’ve been following your walk troughs for a while now.
Fher~
Did you get the one where you talk to Marlene about the three dead fireflys
Yeah the three soliders on the bridge with Marlene .
Nice! I have run the game a few times start to finish but always miss something at some point. I have found everything on separate occasions just never in a single session. Figures huh? This will be a handy reminder.
(Even though it’s hard to miss) There’s a conversation you have with Tess in the slums. Right after you encounter the spores and crouch into the hole there’s a dead man that you have conversation about.