What to know
- You must help Arthur by collecting three jungle quest items before opening the Secret Chest.
- The chest rewards 25,000 Cash and 110 Shards after using the Key.
- The Secret Artifact requires Mutation Liquids, Sacabambapis, and 100,000 Cash.
- The artifact grants +125kg Weight and +15 Damage, with a slight Oxygen reduction.
If you are progressing through Abyss and looking for stronger late-game gear, the Secret Artifact questline is one of the most rewarding side objectives. It combines jungle NPC missions, rare fish farming, and a significant cash investment, but the payoff makes it worth the grind.
Quick overview of the Secret Chest and Artifact quest
| Feature | Requirement | Location | Reward |
|---|---|---|---|
| Arthur’s Quest | Harpoon, Backpack, Tube | Jungle Biome | Key |
| Secret Chest | Arthur’s Key | Lower section of map | 25,000 Cash + 110 Shards |
| Secret Artifact Quest | 5 Mutation Liquids, 3 Sacabambapis, 100,000 Cash | Jungle Biome NPC | Secret Artifact |
| Secret Artifact Stats | – Oxygen (slight), +125kg Weight, +15 Damage | Equip in Artifacts | Strong combat boost |
How to open the Secret Chest in Abyss
Before you can access the Secret Artifact, you need to complete Arthur’s jungle questline.
Arthur’s jungle quest explained
Arthur is a human NPC located in the Jungle Biome. When you speak to him, he asks for three specific items: the Harpoon, the Backpack, and the Tube. These items are not found randomly in your inventory; they are obtained by completing tasks for different monkey NPCs scattered around the jungle.
The Jungle Biome serves as the central hub for this entire process. All monkey NPCs and required fish are tied to this region, so expect to spend most of your farming time here.
How to get the Harpoon
The Harpoon is obtained by completing a monkey quest that requires you to deliver specific materials.
Step 1
Travel to the Jungle Biome and locate the monkey offering the Harpoon mission.
Step 2
Collect 2 Trout with Mutation. These require catching Trout that spawn with mutation effects, so focus on active fishing spots and weather boosts.
Step 3
Collect 4 Bananas. Bananas are obtained randomly while fishing. When you see the small chest icon during fishing, successfully catching that fish gives you a chance to receive either a Banana or a Geode.
Step 4
Return the required items to the monkey to receive the Harpoon.
How to get the Backpack and Tube
Two other monkey NPCs in the Jungle Biome provide the Backpack and Tube through similar task-based missions.
Step 1
Locate each monkey NPC in the Jungle area.
Step 2
Complete their specific requested objectives. These typically involve gathering certain fish or jungle-related materials.
Step 3
Turn in the required items to receive the Backpack and Tube.
Once you have all three items, return to Arthur.
Receiving the Key and opening the chest
Step 1
Deliver the Harpoon, Backpack, and Tube to Arthur.
Step 2
Arthur rewards you with a Key.
Step 3
Travel to the lower section of the map where the Secret Chest is located.
Step 4
Use the Key to unlock the chest.
The chest rewards you with:
| Reward | Amount |
|---|---|
| Cash | 25,000 |
| Shards | 110 |
This completes the first half of the Secret progression.
How to obtain the Secret Artifact
After finishing the chest mission, you can pursue the Secret Artifact by interacting with another NPC in the Jungle Biome.
This quest is significantly more demanding and requires rare materials plus a large cash payment.
Secret Artifact requirements
| Requirement | Amount | Best Farming Location |
|---|---|---|
| Mutation Liquid | 5 | Biome 1 (especially during rain) |
| Sacabambapis | 3 | Jungle Biome |
| Cash | 100,000 | General gameplay & farming |
Farming Mutation Liquids efficiently
Mutation Liquids drop from specific mutated fish. While they can technically appear in multiple biomes, Biome 1 during rain has proven to be the most efficient farming location.
Step 1
Wait for rain weather conditions.
Step 2
Fish actively in Biome 1.
Step 3
Target mutated fish variants to increase your Mutation Liquid drop chances.
Rain increases activity and spawn frequency, making the process faster.
Catching Sacabambapis
Sacabambapis is a Legendary fish exclusive to the Jungle Biome.
Step 1
Fish in the Jungle Biome only.
Step 2
Use upgraded rods and improve weight capacity to handle heavier catches.
Step 3
Be patient, as legendary spawn rates are naturally low.
You must catch three Sacabambapis to fulfill the requirement.
Completing the artifact quest
Step 1
Gather 5 Mutation Liquids.
Step 2
Catch 3 Sacabambapis.
Step 3
Ensure you have 100,000 Cash.
Step 4
Return to the quest Monk NPC and submit all requirements. You will receive the Secret Artifact.
Secret Artifact stats and performance impact
The Secret Artifact is designed for players entering tougher content and deeper dives.
| Stat Change | Value |
|---|---|
| Weight | +125kg |
| Damage | +15 |
| Oxygen | Slight decrease |
The +125kg Weight increase is extremely valuable for extended farming runs, allowing you to carry more loot before surfacing. The +15 Damage boost improves combat performance significantly, especially against stronger underwater threats.
The only downside is a minor reduction in Oxygen capacity. If you already have solid oxygen upgrades or supporting artifacts, this drawback is manageable.
Why this questline is worth completing
The Secret Chest and Secret Artifact questline in Abyss combines jungle exploration, rare fishing mechanics, and resource management into one rewarding progression path. By completing Arthur’s mission first and then farming Mutation Liquids and Sacabambapis, you unlock a powerful artifact that enhances both combat strength and carrying capacity. If you are pushing toward deeper content, this is a questline you should not skip.
Although the grind involves legendary fish farming, RNG-based Banana drops, weather timing, and a large cash investment, the overall progression value is strong. You gain immediate currency from the chest and long-term combat and farming efficiency from the artifact.
If you are aiming to optimize weight capacity and damage output without sacrificing too much survivability, the Secret Artifact is one of the most balanced high-tier items currently available in Abyss.
