Mission 11 - Life
Collectible #53 - Promo Poster
As soon as the mission begins, turn around and head over to the Zurich Coffee House across the road. On the wall beside a door you’ll find a Promo Poster just waiting to be grabbed and added to your collection.
Collectible #54 - Prototype Robot Part
After leaving the lift with Kane, follow the marker until you come to an office with a large glass display directly in front of you when you enter. Turn left and you’ll find a Prototype Robot Part on a desk with monitors on it.
Collectible #55 - Fulgurite
After entering the Egyptian desert-esque dreamscape you’ll come across one of the temporary walls, with a set of buildings behind it. Deal with the enemies that materialise through the door, then head to your left. You’ll see a stone block beside the left-hand building, climb it and use it to climb the two ledges above. At the top, go right around the wall then wall to the end. Climb up one last time and you’ll see a Fulgurite in front of you.
Collectible #56 - Raven Feather
The final collectible can be found after you begin the purge of Corvus. While the screen says ‘Purge’ and a counter slowly rises to 100%, move out the door and towards the big ‘Coalescence’ sign. There’s a desk there - move to the other side of it and you’ll see a rather fitting Raven Feather waiting for you.
Congratulations, you've found every collectible in Call of Duty: Black Ops 3 and unlocked the Curator trophy or achievement.