Doom: The Dark Ages – How To Find All Secrets | Chapter 18 Guide

Welcome to the Belly of the Beast. In Chapter 18, Doom Slayer is eaten by an enormous Old One — you’ll have to fight your way out to 100% this very squishy stage of Doom: The Dark Ages. You’ll have to trudge through stomach acid and punch through gross alien organs to escape the titanic creature’s guts. Like a true Doom Guy, you’ve got to rip and tear through some huge guts. The hugest guts ever.

Challenges | Chapter 18

• Swallowed Whole: Complete the optional encounter in the stomach.

The optional encounter is found near the end of the chapter, on the right side as you progress toward the last weak point. Check the full guide below for the exact location.

• Toe-To-Toe: Parry Cosmic Baron demons 10 times.

A Cosmic Baron appears early in the chapter. After arriving in the room with the giant organ, you’ll begin a long enemy encounter. A Cosmic Baron appears here — instead of killing it, play defensively and parry its attacks 10 times to unlock this challenge early.

All Collectibles & Secrets Locations | Chapter 18

Demonic Essence: Earn +10 maximum armor during the first major demon encounter in the chapter. After approaching The Organ, you’ll need to defeat an Acolyte Leader. Defeat it and perform a Glory Kill to collect its heart.

Secret #1 (Gold x50): At the bottom level of The Organ area, destroy the first green pustule to change the landscape and open a nearby doorway — check the map above and go to the location to find a newly accessible gold chest.

Secret #2 (Ruby): Leaving the first arena, use the mechanical switch with the Shield Throw to enter another section of the giant monster’s body. You’ll reach a slimy room with a Shield Jump and a wall of guts to climb up. At the top, turn around and jump the gap, dropping into the intestine-like tract. It leads to a Ruby upgrade gem.

Secret #3 (Gold x50): Right next to the second organ weak point, look above at a high ledge — there’s another green body dripping with slime. Throw your shield and Shield Jump up there to get a large treasure chest.

Secret #4 (Life Sigil + Gold x6): Destroy the second organ weak point, then drop down to the bottom floor — on the path leading to the Sentinel Shrine. There’s a hole in the flesh wall that’s too high to reach. To get inside, look at it from the right angle to spot a green slime body. Shield Throw and Shield Jump inside the tunnel to reach an extra life.

Collectible #1 (Codex): On the path to the third organ weak point, look on the left side near the end of the demonic encounter area, where the stomach fluid flows over the ledge. There’s a Codex page here to collect.

Secret #5 (Gold x7) + Collectible #2 (Toy): From the Codex, drop down and go straight ahead to find an optional blue gear symbol switch. Use it to unlock the path to the optional stomach encounter. Completing this will unlock the Swallowed Whole challenge.

• For completing this tough challenge, you’ll also find a collectible toy.

Secret #6 (Life Sigil + Gold x13): On the path to the third weak point, look on the outer wall for an optional path leading to a tunnel full of chomping teeth. To bypass the teeth, look above you. There’s a switch that reverses the direction of the teeth, allowing you to pass through and collect an extra life.