Once you've destroyed it, go into the huge room nearby and you'll find a Rune Trial for Dazed and Confused on a machine here. You'll find the second Argent Filter here, at the back of the hall here. Once you've found the Elite Guard, head back to the Gore Nest you just destroyed, then look at the round building and go through the door on the left. Once you've destroyed it, go towards the round building and look for a catwalk on the right side of it.

Heading back to the blue forcefield, you'll find some stacked crates that you can climb to find yet another Gore Nest. There will be some Imps, as well as an Argent Cell around the yellow machinery that will help you out a lot. Next, go back to the blue forcefield and go left through a door there. There is also a Argent Filter in the other room that you need to destroy. You'll find some Possessed here, a Data Log, and a Chainsaw. Heading back to the blue force field, enter the Cargo Station which is on the other side of the area from the blue force field. Heading back up, don't go all the way, you'll find an area to the right that you can follow to find an Elite Guard at the end of it. Head down it and to the right side you'll reach a Field Drone.

Look right and then jump down onto the ledge in the ravine. Once you've destroyed it, begin by heading down the path to the left of the blue forcefield. Continue past the metal on the left part of the area and continue straight, you'll find a Gore Nest here. Once you head through the next door after completing the classic map, you'll find a lot of demons in the next room including a Hell Knight and some Possessed Security. Not only that but you'll find a Classic Map lever for Toxic Refinery behind some barrels in the area. You can then find a Data Log by going up the stairs nearby and then heading left. The challenge is defeating 15 imps in a specific time limit, although the time limit increases when killing the imps and doing glory kills.

You'll find a Rune Trial here (the green rocks) for Vacuum, which specifically sucks items towards you easily. Head towards the lower level of the tower and you'll find a ledge there that you can climb to reach a rocky area. After completing Mission 3: Foundry and starting the new mission, go upstairs and go outside.

Doom shut down the portal secrets