The Foundation

Head to the Director's Office and then to the Hotline Chamber. Use the telephone to speak to the Board and learn of a threat to the Oldest House.

Return to Central Executive via the Director's Office and fast travel to Foundation. The door you are looking for is right next to the control point (a designated safe area). Interact with it to go through.

Head down the tunnel until you come to a locked door. Launch the power core into the outlet and go through.

Continue down the tunnel until you reach Research Site Gamma. Look for a tape recorder on the ground that plays the Log 1: Discovery Ash tape.

Continue to the next tunnel. As you do so, you will automatically receive a new Hotline entry from Marshall, The Foundation. Levitate (a special ability allowing you to jump and hover) across the gap in the cave floor and continue to follow the tunnel until you are attacked by three Hiss Charged (a type of enemy).

You will emerge in a cave with three other tunnels leading from it. The tunnel to your right leads to a loot container while the one to the left is blocked by a void that you are not able to Levitate across. Head down the tunnel opposite to the one you came in from, continuing towards Research Site Delta.

As the cave opens up in front of you, you will see three Hiss hanging from the ceiling. After dealing with them, claim the Cave System control point. There is a locked door to your right that you cannot currently open, so Levitate across the gap in front of you and continue down the tunnel.

When the cave opens up again, look on the floor to your left for a folder with the Cave Paintings research. Continue across one of the bridges spanning the chasm where you will be attacked by several Hiss Sharpened (fast moving enemies that use a pickaxe). Use Launch (a telekinetic ability) to take them out. You will automatically unlock the Hiss Sharpened research after the encounter.

On the other side of the chasm, grab the contents of the loot container near the earth mover and then examine the folder on the ground near the shelter for the Relocation Order correspondence. Go up the ramp in front of you to a cave with geysers in the floor that erupt frequently.

Levitate up to the ledge on the left to avoid them. Make your way back down to the exit.

As you go through the next cave, look out for a folder on the ground to your right containing the Foundation Accident correspondence. Continue forward and claim the loot container by a blocked cave entrance. Press on to the Cave Bleed, an area where the Astral Plane is intersecting with the material world.

Levitate across to the first platform and you will see enemies on the platform ahead of you. These are Astral Copies (mannequin-like figures). After clearing the enemies, you will unlock the Astral Copy research. Use the other platforms to get across to the other side.

As you make your way down the next tunnel, you will see Marshall ahead of you. Use Levitate to cross the gap in front of you and follow the tunnel to the end to emerge in a large cavern called the Crossroads.

Claim the Crossroads control point. Go into the building to your right where you'll find a loot container. In the other building, find a tape recorder with Log 2: Foundation. Back outside, search the shelter to the left of the control point for the Leylines research and the other shelter for the Foundation Pillar research.

Before checking out the very obvious onyx structure, go to the right of the area and look down to see a series of ledges you can climb down. Drop down the first two to find a loot container. Hugging the wall to your left, look for a ledge you can walk along. Follow the ledge round until you come to a cave mouth. Squeeze past the wooden structure blocking the entrance and head down the tunnel. Examine the folder on the floor for the Unacceptable Behavior Memo. Just past that you will receive notification of discovering a Hidden Location. If you open the loot container, you will receive a personal mod (a modification for your abilities), but will also trigger an ambush from a large number of Hiss Charged. Head back out and continue down to the lower ledges to find another loot container right at the bottom and then make your way back up to the Crossroads.

Examine the large onyx structure. You will be addressed by the board who ask you to choose an ability. The choice on the left unlocks the Shape ability while the one on the right chooses Fracture. Choose Fracture for the time being - you will be able to unlock Shape later.

Shoot the crystal formations blocking your way and go through. Levitate to the next platform and shoot more crystals blocking your way. Shoot some crystals above you and Levitate up and go past. Shoot the next set blocking your way and then shoot a crystal to lower a block that you can use to progress.