Letheia Labs

Letheia Labs is an extra dungeon categorized as threat 6. Talk to S.A.I.L. to beam there.


 * Acquisition : You will need to complete the space encounter/dungeon Letheia Fleet. At the end of the Letheia Fleet, you will find a map, interact with it to receive this quest and unlock the location in S.A.I.L. interface.


 * Quest Reward: 1 Neutron Star Orbs, 20 Dense Alloy, 20 Refined Aegisalt, 1 Erchius Horror Figurine, 3000 Research


 * Items Requirement : The Sonic Sphere is required. An oxygen source is needed for a path.


 * Other : The different people you recruit at the Ark will make a lot of comments during this mission. You may want to recruit Baron before doing this mission if you want to see all dialogues.

Dungeon Guide
As soon as you beam to the dungeon, S.A.I.L. will warn you that the Sonic Sphere tech is required. Head to your left and follow the only path available until you reach the first corpse. You will find plenty of those through the dungeons and they can be destroyed with a weapon hit for some ressources (like Raw Meat... Sometimes it's better to not know where your food comes from i guess). Two path opens up here: the path to the left lead to some extra container and dialogues, while the path to the right is the main path.

Optional Left Path
After reaching the middle of the room labelled "Level C Dorms", the wall in the top left will blow up, releasing some ennemies in the room. A Tentaspawner will appear in the cavity opened by the explosion and start spawning Tentagnats to attack you. After dealing with them, keep going to the left and you will reach the bedroom. Go to the far left of the room and you will find a console. Activate it. As you come close to the console, the roof in the middle of the room will blow up, releasing 4 Moontants. Exit the bedroom and go downstairs. The shower to your right are empty, head to the kitchen to your left. Once you are in the middle of the room, 7 Tentagnats will come out of the vent. If you activated the console in the bedroom, a small passage will be open at the far left of the room. Use your Sphere to go through it and loot the containers and the corpse in the small room. Now you can backtrack to the first crossroad and head up to the main path.

Main Right Path
Head toward the right and watchout for the barbed wire laying in the room. In the next room, you will find the first Lava Lamp Server. S.A.I.L. can read those for you when you pass in front of them, giving you some explanation of what happened in the labs. You will then reach an elevator leading below and a path leading to the left. Once again, the path to the left is purely optional and lead to a room containing a Lava Lamp Server guarded by 10 Tentagnats that will start spawning once you approach the server and the walls blows up. Head back the the elevator and use it to go down. Do not jump down as it is a really high fall and the fall dammage will likely kill you. Once you are at the bottom, you can see a small passage in the wall to your right. The Microsphere tech can allow you to skip a part of the dungeon here, leading you into the Vents.

Go to the left and enter the room labelled "Bioweapons Class 4". The exit to the left of the room is locked and you will need to activate the console to the right of the room to open it. However the exit will not immediately open. Instead, the door behind you will lock and swarm of ennemies will start attacking you and you will need to hold off until the gate open. To help you with that, a turret that you can activate if placed here. Press the big red button and watch the turret fire, killing pretty much everything in its way. It will need to recharge for 5 seconds before firing again. In total, 19 Moontants will fall from the roof and 10 Tentagnats will come out of the vents. Once the exit open, two paths will be open to you, both leading toward the end of the mission. The path to your left leads you to some kind of creature Cbservation Cell, while the path leading below lead to the Vents.

Observation Cell
The first room holds a pool of slime with a few platforms above it. Make your way on the platforms but be warned, once you reach the 3rd platform, ennemies will start appearing. 4 Tentabombs will come from the roof, while 2 Tentaspawns are hiding in the pool of slime. After crossing the slime pool, do as S.A.I.L. tell you and stand in the middle of the fence and charge up your Sonic Sphere. Releasing it will propell you into the small passage leading to the next room. You will find another Lava Lamp Server in this room and the path by which you came will lock behind you. Exit the room to the left and head downstairs. Another Lava Lamp Server awaits you, aswell aswell as some free pixels and a pet healing station. Head back upstairs and make your way to the left. You will reach a room with a red pressure plate on the ground. It opens the exit to the left but only stay open a short time. Charge your Sonic Sphere on the pressure plate, then release it to pass the gate before it closes. Go down the stairs and enter the room with the huge containers. Shoot the barrels at the left of the room to blow up a hole in the ground and jump down there.

You will land in a pool of slime and a lot of Ruin blocks everywhere. Go to your left and cross the small slime pool. In the middle of the pool, 4 Tentacrawler will spawn inside the pool and start chasing you. Two new paths will be open to you: either keep going left or dive in the slime pool.

Slime pool
At the bottom of the pool, 2 barrels can be destroyed to blow your way to the room downstairs. You can find a lot of healing items inside the shelfs and other container of this room. Then head to the left and open the door with the console.

Ground path
If you head to the left, you will find another big empty room with a small pool of slime. You guessed it right, once you are in the middle of the pool, 7 Tentabombs will spawn and try to blow up on you. Then head into the small passage with your Sphere and you will roll down to a room below.

Both path leads you to this room, head to the left and the door will open for you, but will lock behind you. Keep going to the left and you will reach the room of the Last Stand.