I have some good news and some bad news regarding the seventh mission of Doom Eternal. The good news is that there are fewer collectables here compared to the previous mission. The bad news is that there are still 20 of them. Once you have them, the vast bulk of the collectables will be yours, so let’s get into it.

The seventh mission of Doom Eternal has 20 collectable items. You’ll also need to find the various secret encounter locations and the Slayer Key, so it’s no mean feat to get everything.

As always, it’s worth noting that getting to the end of the mission enables Fast Travel so you can pick up collectables that you missed. The automap also helps here and the automap is found when accessing the core from the maintenance shaft. It should be right in front of you by the turbines.


Here are the locations of the collectables hidden in the seventh mission of Doom Eternal.

Mars Core collectable locations

Secret encounters

  • Secret Encounter #1: It is next to Praetor Suit point #2, which is accessed after getting the BFG 9000 and hopping through the teleporter. Jump to the next big area. After the first major fight in this area, a hole will open up. Go down it and look to the wall that has been blown open. Jump and dash around the circumference of the building to the left to find a gap to find the encounter.
  • Secret Encounter #2: Use the monkey bars in the room with the tentacle pods, but go down the hole. Proceed through the door labelled “Maintenance 02” and use the portal inside. You should find it on the other side. This is in the opposite direction to the waypoint marker and the harmful electric pods.


  • Big Ba-Da-Boom: Kill 40 demons with a very big gun. We’ll give you three guesses what that very big gun is.
  • Disarmament: Destroy three arm cannon Weak Points on Mancubi. These are the arm cannons and I recommend using the Precision Bolt weapon mod for this.
  • Lock and Key: Find the Slayer Key.

You shouldn’t really have too hard a time with the next mission’s list of collectables. Most are on the main path and the one that’s slightly better hidden is still very reachable. To make sure you don’t miss out on any of them, have a look at our guides for all the other collectables in Doom Eternal:

Doom Eternal Mars Core collectbales

Doom Eternal collectables

Doom Eternal guides series