Cthulhu: The Cosmic Abyss – Chapter 3 Walkthrough

Cthulhu: The Cosmic Abyss is a single-player adventure game where you play the role of Noah Williams. You’ll have to solve a series of puzzles as you make your progress towards uncovering the secrets of the Deep Ones. So far, Noah has followed Andrew Marsh to the Temple. Now, you’ll have to look for any survivors in the area and find Marsh as well.

For more information on the game, please visit its official Steam page here.

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The Temple

As you arrive in the ancient city, walk towards the structure through the terrain. If you step on the ledge towards the edge of the cliff, it will break, and you’ll fall into the water. You can get to the ancient building from there.

This ancient building is a temple, with some statues of Cthulhu. As you enter, your corruption will increase. However, you have to keep going ahead.

You can also use the Hybrid Mucus frequency to find the way ahead. You’ll still be able to look for the footprints of the strange creature that wrecked the PIT station.

As you keep going, you’ll find the bodies of several Ocean-I workers who have been attacked by the creature. Inspect the bodies and look for clues. You’ll find some voice recorders and computers that can give you more information as you follow the footprints.

Sacrificial Altar

You’ll hear the voice of someone as you walk deeper into the temple. There’s a camp here, but no one is alive here. You’ll still have to look around for minor clues. Just beyond the camp, you’ll find a man attached to a sacrificial altar.

He’s still alive, and his name is David Curwen. He’ll tell you that Andrew Marsh just went through the portal. He’ll also tell you that Marsh’s team was trying to conduct a ritual here, but since Anastasia backed off and ran away, the guardian of the portal is angry.

The portal’s guardian is the reason why no one is left alive at the camp. You also can’t swim through the water to get to the portal as long as the guardian is there.

Analyze the Sacrificial Altar to get the Ancient Blood and Human Blood frequencies. If you look around the Sacrificial Altar, there’s a laptop and a small stone tablet nearby.

Inspect and analyze the stone tablet. You’ll get the Basalt frequency. The Tablet is in an ancient language, and you’ll have to find a way for Key to decipher it.

Near The Sacrificial Altar

If you interact with the computer nearby, it won’t turn on. The battery is spoiled, and you’ll have to find a new one that works. If you scan the battery, you’ll get the Potassium Hydroxide frequency, which can be used to find other batteries.

There’s also a metal plate with a slot for a sphere. There’s also a water pond here that’s connected to the body of water leading to the portal. You’ll also find the body of a woman inside the water, but she won’t respond.

If you go ahead further, you’ll find some desks, documents, and computers set by the Ocean-I team towards the edge of the cliff. There’s also a crown (Tentacles) here. If you look at the clues, it looks like there are a total of three crowns.

Scan the crown to get the Orichalcum frequency. You’ll need that to find the other two crowns.

Finding Batteries

There are a few computers in the area that require batteries. However, not all batteries will work. You’ll need to find the one with Lithium in it.

Once you’ve found a battery with Lithium, scan it to get the Lithium frequency. If you use the Lithium frequency, you’ll be able to find all the batteries that will work with the computers in the temple.

You may also find some Lithium batteries in the Ocean-I camp before the sacrificial altar. Use one such battery with Anastasia’s computer, near the Sacrificial Altar.

Doing so will allow Key to translate the ancient language found on all the Basalt walls in the area.

Corruption And Non-Corruption Paths

If you want to follow the Corruption Path, you’ll have to find the three crowns and place them on the three skeletons. However, before you can place the crowns on the skeletons, you’ll have to bless them at the Sacrificial Altar first.

For the Non-Corruption path, you’ll have to find three mechanical cubes and place them on the circular metal plates in the area. You’ll also have to find the right frequency to make the cubes react.

Ocean-I Lab

There’s an Ocean-I Lab, southeast of the Sacrificial Altar. You’ll find some platforms next to the walls here. Go to the camp and gather clues.

You’ll find a mechanical cube here that reacts to frequencies. You’ll also find a sample for Invasive Algae, which can allow you to break some platforms to unlock new locations. Don’t forget to scan it.

Hall Of Secrets

If you follow the path to the right, just behind the Sacrificial Altar, you’ll find that it leads to the Hall of Secrets. There’s also a statue with three eyes on this path.

Now, if you go ahead, you’ll enter a dark chamber. It is a maze, and the only way to progress here is to set your sonar frequency to Ancient Blood.

This will allow you to spot a trail on the ground. Keep following the trail. And, you’ll eventually arrive at the area with a skeleton.

There are three Basalt tablets behind the skeletons and ahead of the platforms. There’s also a metal plate here with a slot for a sphere.

You can also find a mechanical cube inside the water body near the skeleton. Use the Alloy frequency to pinpoint the cube’s location.

Furthermore, if you’re going for the corruption path, you’ll need to place the Crown (Eye) on the skeleton’s head after blessing it. If you’ve done it correctly, the skeleton’s hand will turn into a begging position, and a trail of slime will erupt from it.

You can find the Crown (Eye) behind the Sacrificial Altar. It’s difficult to spot, but you can easily find it by using the Orichalcum frequency with the sonar.

Submerged Hall

The Submerged Hall can be reached by going behind the Sacrificial Altar. The entire area is covered in red liquid, which is a mix of water, blood, and other stuff. There’s also a statue with fangs near the entrance to this area.

When you walk into the area, you’ll find an altar in the middle. There’s a statue with fangs to the right here. Approach the statue in the chamber, and you’ll find a path submerged under it.

You can’t see anything in the red liquid, so you’ll have to rely on your sonar. Repeatedly use the sonar to get the idea of the layout to progress.

Once you’re under the liquid, use the Orichalcum frequency to look for the crown and keep going straight. You’ll eventually come out ahead.

You’ll find the bodies of some Ocean-I researchers here. There’s a hole on the other side of this area with red liquid inside it. If you jump into it, you’ll find a huge pile of bones. The Crown (Claws) can be found here.

Once you’ve taken up the crown, return to the red liquid and set your frequency to Human Bones. If you hold the button for the sonar, it will increase the range. After that, you have to follow the path under the liquid that leads to the skeleton on the throne.

After you get there, you can place the Crown (Claws) on the skeleton’s head after you’ve blessed it. There’s another hole right next to the skeleton with red liquid in it. You’ll find a metal plate under the liquid, as well as a mechanical cube.

Blessing The Crowns

Blessing the crowns is required for the corruption path. You can bless the crowns by simply putting them inside the pocket of blood behind David Curwen’s Sacrificial Altar.

Once a crown has been blessed, it will be covered in blood. You’ll then have to place the crowns on the skeletons.

After you’ve placed a crown on the skeleton’s head in the Hall of Secrets and the Submerged Halls, another skeleton will appear in the main area.

Metal Plates And Mechanical Cubes

To place the Mechanical Cubes inside the metal plates, you’ll need to find a frequency that can turn the cubes into spheres.

Set your sonar to Invasive Algae and use it to find breakable platforms. There are some brackets outside of the Ocean-I lab, where you found the first mechanical cube. Get on top of the brackets and use the sonar to find some breakable platforms under you.

Here, you have to jump on the platforms from the brackets. This will cause the ground to break, and you’ll end up in a new area. Here, you’ll find a submerged mechanism.

If you analyze the mechanism, you’ll unlock the Electrum frequency. This mechanism is currently broken, but you can find a cylinder in the same body of water.

Place the cylinder on the mechanism, and it will start to work. Now you have to find a way back to the main area. There are two drainage spaces in this location.

Note that there’s a metal plate above the mechanism with a slot. But you don’t have to place the spheres in this metal plate.

Jump on the left drainage and go to your right. There’s a tiny space here, but you can get through it if you crouch down. Use the rubble here to get back up. You’ll then arrive near the Ocean-I Lab.

Now, you have to place each of the metal cubes in the metal plates. Use the Electrum frequency to turn the cubes into spheres, and then place them in the metal plates.

The first cube can be found in the Ocean-I Lab, while the other cubes can be easily found near the metal plates in the Submerged Hall and in the Hall of Secrets.

To The Portal

After you’ve used the crowns or placed the spheres in the metal plates, the guardian won’t bother you anymore.

You can dive into the pool of water in the centre of the area. There’s a small tunnel underwater that will lead you to the area with the portal. Pass through the portal, and that would be the end of Chapter 3.

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This concludes the walkthrough for Chapter 3 of Cthulhu: The Cosmic Abyss.

You can also check out the game’s main hub here for the next chapter. If you’re looking for more to read, please visit these pages below:

• Into Indie Games Homepage
• OPUS: Prism Peak – Walkthrough Hub
• MOUSE: P.I. For Hire – Walkthrough Hub
• Regions Of Ruin: Runegate – Walkthrough Hub
• Gecko Gods Complete Walkthrough Hub