This will guide you trough the steps and things you will need for acquiring the horrific abyssal treasure, one of the objectives of Phase 5 of the Expedition #1: The Pioneers.
Things you will need
- Dreams of the Deep secondary mission started or finished
- The Nautilon Exocraft with High Power Sonar installed (Submarine)
- A Hypnotic Eye
- A freighter with an Orbital Exocraft Materialiser installed (optional)
- Lots of patience (important)
This objective revolves around you exploring and scanning the water planets of No Man Sky in search of the horrific abyssal treasure, so having a functional Nautilon Exocraft with the High Power Sonar is necessary. You can get the Nautilon Exocraft and the High Power Sonar for free by doing the first steps of Dreams of the Deep until you get the High Power Sonar and is prompted to use it. When you acquire both of these things, you can choose to finish the Dreams of the Deep mission or leave it for another time. Keep in mind that you will most likely need to leave the system that the mission is taking place, meaning that if you leave the mission system, you will need to come back to it to finish the mission, or restart the mission on the new system you currently are.
You will need to offer the Hypnotic Eye to the refracting light on one of the underwater ruins in order to get the horrific abyssal treasure. The Hypnotic Eye can be acquired through the mission Dreams of the Deep on one of the many Sunken Buildings you will come across, each one has two Abyssal Horrors, and killing them will drop the Hypnotic Eye. The Hypnotic Eye can also be found on Derelict Freighter containers or dropped by any Abyssal Horror found on any big body of water.
A freighter with an Orbital Exocraft Materialiser will help you speed up the process drastically. It allows you to summon any exocraft in any planet on the same system that your freighter is positioned, and since you will most likely be jumping into multiple systems in search of the abyssal treasure, this is the quickest way of summoning you Nautilon on the planet you are.
You can get the Orbital Exocraft Materialiser from the Construction Research Station aboard the Space Anomaly for 15x Salvaged Data.
Acquiring the Horrific Abyssal Treasure
Upon reaching a water planet, find a really big body of water and land somewhere in the middle of it using the little islands that tends to spawn in these biomes. After you exit your ship, summon your freighter on the system if you haven’t already and then summon the Nautilon Exocraft on the water using the quick menu.
Now comes the part where you need lots of patience, you will need to use the scanner on the Nautilon Exocraft using the quick menu to search for any underwater ruins. If you have any underwater ruin within scanner range, you will get it tagged on your screen and you can go there. If your scanner didn’t find anything, you need to relocate to a different area of the ocean and repeat the process, summoning your Nautilon Exocraft and scanning for underwater ruins until you find one.
Once you manage to get an underwater ruin tagged on your screen, you can exit the Nautilon Exocraft, hop onto you ship and go to the underwater ruin by air, it will be faster. When you get close, land, exit you ship and dive to the underwater ruin until you find the refracting light on the ruin structure.
Now you need to interact with the refracting light, upon interacting with it, you can get two sets of dialogue options, one is “Accept the Waves” or “Decline”, if you get this set you should choose “Accept the Waves”, that will give you a trident key that you can use to open the buried cache on the underwater ruin similar to how the ancient ruins work. The other set is “Listen” or “Offer Hypnotic Eye”, if you get this set of options you should choose “Offer Hypnotic Eye”, and upon ending the dialogue you will be rewarded with the horrific abyssal treasure and completed the expedition objective.
It can take multiple underwater ruins until you get the option to offer the hypnotic eye, personally I got mine on the 7th underwater ruin. After interacting with the refracting light, if you didn’t get to option to offer the hypnotic eye, you can spawn the Nautilon Exocraft again and use the scanner to find another underwater ruin. If you find none, exit the planet and go to another water planet either in the same system or a different one, it doesn’t matter. Keep in mind that the Nautilon scanner can find an underwater ruin that you have been already, and you will not be able to interact with the refracting light you interacted already, so I recommend placing a personal marker with the player scanner on the last underwater ruin you’ve been just so you know you’ve been there already when the ruin gets tagged on your HUD.
Some people reported finding the horrific abyssal treasure on the cargo containers of underwater crashed freighters that you can also find using the Nautilon Scanner, but I haven’t found any source nor confirmed personally. If you have found yours that way, please confirm it in the comments section so more people can be aware of this method.
If you found any mistakes or would like to contribute to this guide, please leave a comment or send me a message, I will do my best to make this guide as accurate as possible.