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 a swarm of enemies will start attacking you and you will need to hold off until the gate opens. 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 opens, two paths will be open to you, both leading towards the end of the mission. The path to your left leads you to some kind of Creature Observation Cell, while the path leading below leads to the Vents.

Observation Cell

The first room holds a pool of slime with a few platforms above it, and an extra exit, which can be accessed using the double jump and sonic sphere, containing a switch and a chest. Make your way on the platforms but be warned, once you reach the 3rd platform, enemies 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.

Vents

Head down the stair to reach the vents. They are a little maze that you will need to navigate to reach the exit, with a few extra chests with random loot hidden along the way. Here's the direction you need to take at each crossroad to reach all the chests and the exit, starting from where you enter the Vents:

Extra chests

Here's the direction you need to take at each crossroad to reach all the chests, starting from where you enter the Vents:

• Go to the left, then to the left again. You will find a dead end with a chest and a corpse. Going near the chest will blow up two walls, poison coming out of the first hole and flooding the area with the chest, and the second hole hosts 4 Tentaghosts.
• Go down, then right (7 Tentagnats will ambush you), then down. A chest lies in the poison pool alongside 2 corpses.
• Go down, then right (7 Tentagnats will ambush you), then right, then up. You'll find a chest and a corpse in a dead end.
• Go down, then right (7 Tentagnats will ambush you), then right, then down (4 Tentacrawlers will ambush you), then right then left. You'll find a chest in a dead end.

Exit of the Vents

• Go down, then right (7 Tentagnats will ambush you), then right, then down (4 Tentacrawlers will ambush you), then left. A proximity scanner will open a gate leading down and you will find in a pond of water.

Head to the left and you will reach a room with a Plasma Lamp Server. Activate the console in this room and backtrack out of the room. A trap leading to the Aquarium is open now. Dive into the Aquarium and start swimming your way through. Head left at the first crossroad for some diamonds and a chest protected by a fish. Then head upward and deal with another fish on your way. 2 Fishes await you in the last part. After killing them, exit the Aquarium by the top left of the water. Go upstairs and a few pixels await you on the right. Then head left, where S.A.I.L. warn you that deadly lasers awaits you. Your running speed is to slow to pass them, but the Sonic Sphere will get you through unharmed. the next room, labelled "Specimens" houses another Lava Lamp Server, but moving to far to the left of the room will blow up some walls and release ennemies at you. Kill the 8 Moontants and the 9 Tentagnats to open the door exiting the room. The top right exit will lead you to a small room with a Lava Lamp Server where Letheia were conducting some... experiments that you can carry on if you want (it doesn't do anything, except maybe showing that you are a monster). Come back in the Specimens room and use the top left exit. Another room with deadly lasers, just use your Sonic Sphere to cross it. Keep going forward and you will reach the Last Stand room.

Last Stand

You will find a pet healing station just before the final room, which you enter with one of those one way door. S.A.I.L. will brief you on the situation: you will need to hold against waves of ennemies (S.A.I.L. tells you that you need to hold for 90 seconds, but you need to kill every ennemy to open the exit, the last ennemies appearing after 90 seconds). You will face hordes of Moontants accompagnied by Tentagnats, Tentaghosts, Tentacrawlers and Tentabombs with them. Like the previous room where you needed to hold off against ennemies, you will have access to 2 turrets that you can manually activate every 5 seconds to clear up some ennemies. Once you are ready, activate the console in the middle of the room and hold your position until everything is dead. The Moontants will fall from the roof to the right and left of the center of the room, sustaining some dammages from the fall. Tentagnats, Tentacrawlers and Tentabombs will spawn right above the the console and the Tentaghosts will spawn to the left and right of the room.

Once everything is dead, the exit to the left open. Take the elevator and you will reach the last room, containing a wall locker,the diamond pedestal to turn in the quest and 2 chests. You will also see 3 locked room under you containing extra chests. To open those, you will need to activate 3 switches scattered through the dungeon. Once you are done looting, press the red button and exit through the teleporter. Do not mind the small passage to the right of the teleporter, it will just bring you back in a previously visited room.

Secret

The secret of this dungeon is explained on this page.