Cthulhu: The Cosmic Abyss Wiki

Cthulhu The Cosmic Abyss — Chapter 2: Excavations

Suit up, underwater PIT station, vault links, labyrinth rift — end of current demo.

Clues & collectibles

  • Lichen stimulant
  • Tablet Electronic Component
  • Hydrogen cylinders
  • Control module recording
  • Copper mountings
  • Astral Stone
  • Ancient Glyph tablet
  • Red rope body
  • Camp photo
  • Monolith evolution

Step-by-step

  1. 1. Briefing and suit

    Suit up after the study briefing. Use the capsule lever when instructed to proceed toward the vault.

  2. 2. Vault and reports

    In the vault intro, link evidence to the PIT Incident Report from Chapter 1 when KEY prompts you.

  3. 3. Underwater PIT station

    Drain the airlock to enter the station. Explore the engine room: lichen as a stimulant clue, tablet on Electronic Component frequency, and hydrogen cylinders for the generator puzzle.

  4. 4. Generator and corruption

    Repair the generator. Corruption effects intensify after this segment — manage sanity and avoid lingering on twisted visuals.

  5. 5. Control module and copper

    Recover the control module recording. Scan copper frequency from wall mountings for another vault link.

  6. 6. Labyrinth rift

    Through the rift: obtain the Astral Stone and the glowing Ancient Glyph tablet. Investigate the body bound with red rope.

  7. 7. Camp and artifact

    At the camp, review the photo and the monolith (evolution point). Place the artifact as directed to close the demo arc.

Sanity tips

Chapter 2 adds longer underwater tension. Take breaks from scanning if corruption audio spikes. Stack vault deductions early for Elementary-style achievements.

More in Sanity guide and achievements.

FAQ

How do I unlock Thanks Key?

Have KEY analyze 25 distinct clues. Chapters 1 and 2 of the demo contain more than half of them if you scan thoroughly.

Where is the quartz alloy?

Near the occult book pages on the shelves in May's house. Scan it on the Mineral sonar frequency when KEY unlocks that step.

I missed a clue — can I go back?

Most demo areas allow free backtracking inside the chapter. If a door locks, reload an earlier save if available.

Hardest achievement in the demo?

Thanks Key or full frequency coverage — both reward slow, methodical scanning.