Doom: The Dark Ages Guide | Sentinel Barracks Collectibles, Secrets and Challenges

Here's a guide on how to get all the Secrets and collectibles and complete all the challenges of Sentinel Barracks in Doom: The Dark Ages.

Game Guide by TauxicPandA on May 28, 2025

In this guide for Doom: The Dark Ages, you'll find all the secrets, resources, and collectibles and finish the challenges for Sentinel Barracks, Doom: The Dark Ages Chapter 4. If you're grinding for 100% completion, you'll need to complete all these challenges and find all the secrets, collectibles, and resources.

Doom, The Dark Ages Guide, Sentinel Barracks, Collectibles, Secrets, Challenges

Understanding the Objectives

There are three challenges in this chapter. One of them requires you to kill 40 demons. If you finish the level and fight enemies, this challenge will be completed naturally. If you follow this guide, you'll get it without having to farm and rescout areas.

The Second challenge is "Plunderer", where you need to loot 150 gold. This will also be completed naturally following the path in this guide.

The third challenge is "Prize Fighter" for getting a three-hit melee combo. You can complete this challenge anytime in the level whenever you feel like it. On harder difficulty, try to distance yourself from a group of enemies and isolate the bigger ones from the crowd so that you can hit the bigger enemies with the combo.

If you are playing on easier difficulty, the first large room you'll enter is a good option to complete this challenge. You can go near them and melee once bigger monsters spawn in that room. There are a lot of melee recharge items everywhere, so you'll never run out of them.

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You don't even have to kill them — if you do the triple melee attack, it'll still count for the challenge. It's risky to complete this challenge on larger bosses or mini-bosses because they can shoot back at you and drain your health very quickly, but the challenge will still count even if they live, so make sure to land proper strikes.

Hell Knight Toy

Loot the three gold bars before you in the big area outside. But don't follow the path that leads downwards. Backtrack a little bit, and to the right, there will be a room. Go inside and keep moving forward by killing all the enemies before you. If you have the shield upgrade, this section is easy to pass.

Once you have cleared the area, turn left. There will be a breakable door. Break the door, and it will take you to a lower area full of additional resources. You can take the Hell Knight collectible from this section.

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Then, move across the bridge to the next chamber. If you haven't tried your melee combo challenge, this is still another ideal opportunity to try it on a mini-boss you'll face on this bridge.

Go to the right half of the room and jump to the elevated platform where a green statue is placed. Climb up, take the gold lined up to the end, and jump down to the switch that sets off a mechanism that pushes a block. Bash the block forward with your shield bash. Jump onto the top of that block, take more gold, and go to the chest nearby to gather even more resources.

To reach the next room, stand on the green platform in the middle and throw your shield at a door that'll rise with an orange marker. Once the path has been opened, jump across.

First Life Sigil

After you have jumped across to the next room, you'll be in a circular arena where you have to tackle a lot of enemies. There is a group of four gold pickups in this room, and as soon as you enter, the game spawns and surrounds you with a bunch of enemies. Kill all the enemies and pick up the loot when the room is safe.

After this, turn left. You will notice a short side path and a lever that you have to interact with. This opens up an entrance to a second secret room. Enemies will spawn from a lower opening area below, kill them, and jump through this opening into the area with two paths. Choose either one of them, as both paths will take you above. Pick up all the extra gold along the way.

Once you are up there, a gate should automatically open to a room with the life sigil in it.

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First Ruby

Go down to the next section. You'll see a ruby hanging from a statue. This one is difficult to miss as you'll see it along the way, completing this chapter.

Second Life Sigil

Before entering the boss fight level, look for a broken bridge; on the left will be the edge of a side platform. Jump upon it. And you'll land in a forest-like area. There'll be climbable structures, so keep climbing until you reach the top. Collect all the gold you can find along the way. After looting the second life sigil, you'll notice a breakable door. Smash it to go outside.

Boss Fight

When you move forward, you'll be in the boss fight arena. There will be two phases in this part. The first boss is blocking green projectiles that he's throwing at you. You will want to use the shield and parry his projectiles.

After you've defeated the first boss, the second boss shows up. Defeat him, and he will drop his heart. Extract it to boost your max armor. The item is also not missable because it's part of the chapter.

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Second Ruby

Once you've killed the boss, you'll be in a new circular region with broken bridges. Jump across the first bridge and land on the second one. Instead of heading straight on, turn around and sprint across the bridge. Jump down onto the hidden lower area. The area is dark and filled with enemies. Be careful and follow the path upwards.

Avoid the enemies if you don't wish for a lengthy battle, and collect the gold on the ground. Then, head back up. When you walk around by climbing the climbable structures and get to the top, you will discover the secret ruby. This is not on the path, so it is easy to miss if you are not taking detours.

Doom, The Dark Ages Guide, Sentinel Barracks, Collectibles, Secrets, Challenges, Second Ruby

Be sure to pick up the gold pickups lying around and head on up to completely clear out the zone.

Cross the bridge and head in the direction of the spiral tower. Inside, there'll be invisible enemies. Clear them out and loot the chest. When you open it, there'll be enough gold to complete the "Plunderer" Challenge.

Weapon Skin

Then, jump over to the next bridge segment. When you arrive here, you can jump down and get a weapon skin. Underneath that, there's gold to collect. Make sure to grab it as you're going down.

You will find yourself in an area with a structure resembling a church. Some pieces of gold are placed in two destructible carriages. Break them and loot the gold.

Codex

Before entering the last boss room, move left and go into the area on your left. You will find one final piece of gold and a crucial codex entry. The codex wraps up your 100% progression and is too easily missed if you rush to the boss room.

Doom, The Dark Ages Guide, Sentinel Barracks, Collectibles, Secrets, Challenges, Codex