Below are the collectibles that can be found during the UAC Atlantica Facility campaign in Doom Eternal: The Ancient Gods Part 1. You will need to collect the codex pages to earn the Required Reading trophy and the Support Runes for the Lucky Charm Bracelet trophy. Locating all the secret encounters will reward you with the Hypersonic trophy!
UAC Facility (Intact) – Get the Seraphim’s Key
Codex: Book of the Seraphs Part 1
This codex is located on the bottom level of the UAC structure near the starting point. It is located in the section of the structure requiring Blue Access. It is across from a set of stairs and a jump pad.
Extra Life
This extra life can be found in the vent shaft above the room containing the Red Access key card.
Secret Encounter
After using the elevator to ascend, head straight ahead and jump on the climb wall across the gap then descend. Turn around and jump across the gap to reach a lower platform containing this secret encounter.
Codex: Book of the Seraphs Part II
After ascending the elevator, you’ll need to disable a giant fan to jump across the gap to reach a platform on the other side. Do so then head forward a short way to reach a lever that needs to be melee’d. Head left past the lever to reach a set of stairs. Go up the stairs to find the codex.
Codex: Book of the Seraphs Part III
After using a fan to launch yourself across a giant gap to the climb wall on the other side, you’ll jump down to a metal platform below. Instead of taking the stairs up, follow the walkway towards a giant sealed metal door. Jump over the railing to the right of the door to reach a ledge. Follow it around to find the codex.
Codex: Book of the Seraphs Part IV
After fighting the Doom Hunter for the first time, head through the doorway to the facility to reach a room containing a set of stairs leading to the second level. The codex can be found on the other side of the stairs.
UAC Facility (Destroyed) – Locate the Seraphim
Slayer Key
After clearing the first area of enemies in the destroyed UAC Facility, you’ll enter a long hallway filled with tentacles. Enter the doorway at the end of the hallway to reach another hallway filled with lasers. Continue heading through the hallway passing the Slayer Gate.
Defeat the Tyrant then continue through the door to reach a loading dock with the area map. Jump up on the cargo to the left of the map and look over the ledge to find some yellow spin poles.
Use the poles to reach a ventilation shaft then crash through it. Follow the shaft to find the Slayer Key.
Support Rune
This rune can be obtained after defeating the above Slayer Gate.
Secret Encounter
After obtaining the dive suit, head back out to the large room and enter the water to look for a breakable grate. Break this then head into the vent shaft to find the secret room containing the secret encounter.
Extra Life
After punching the lever and using the yellow spin bar to jump onto a shipping container, allow the shipping container to take you to a climb wall. Climb up the wall then jump to the platform on the right. Follow the path right to reach the extra life at the end.