Call of the Elder Gods Observatory: Chapter 5 Puzzle Walkthrough - Puzzle

Call of the Elder Gods Observatory: Chapter 5 Puzzle Walkthrough

Master the Call of the Elder Gods observatory puzzle in Chapter 5. Learn the constellation symbols, Yithian numbers, and coordinates to find Pnakotus.

2026-05-20
Wiki Team
Quick Guide
  • Call of the Elder Gods observatory: A pivotal location in Chapter 5 used to determine the coordinates for the Great Engineer's vessel.
  • Constellation Match: Identify the constellation on the ceiling that matches Evangeline's journal sketches.
  • Yithian Era: Use the second era (Dimetrodon) to reference the past and the fifth era (Humanity) for the present.
  • Vessel Coordinates: The final numerical sequence required to launch the ship is 89345.
  • Central Map: Input the Earth symbol and the correct era digit to bridge the gap between time periods.

Chapter 5: Prisoners of Ice Overview

Chapter 5 of Call of the Elder Gods, titled "Prisoners of Ice," takes Harry Everhart and Evangeline Drayton deep into a frozen bunker beneath the Spitzbergen radio station. After escaping the terrifying Polyps, the duo discovers the Great Engineer frozen in stasis. This chapter is heavily focused on metaphysical puzzles, mind-swapping mechanics, and navigating the ancient Yithian city of Pnakotus through Evangeline's inherited memories.

Video Highlights:

  • Communication Setup: How to align brainwaves with the Great Engineer.
  • The Great Library: Navigating the archives to find mural clues.
  • Observatory Mechanics: Matching constellations to planetary symbols.
  • Vessel Launch: Inputting the 5-digit coordinate code.

The initial challenge involves using a communication chair to link Evangeline's mind with the Engineer. This requires precise adjustment of frequency knobs based on brainwave patterns labeled as "Geeignet" (suitable) or "Untauglich" (unsuitable).

Machine KnobCorrect SettingFrequency Result
Knob APosition 3High Resonance
Knob BPosition 1Stable Wave
Knob CPosition 4Peak Alignment
Knob DPosition 3Harmonic Match
Brainwave Tip

When adjusting the knobs, always look for the green light under the Geeignet indicator. If the red light under Untauglich stays on, your frequency is incompatible with the Engineer's neural interface.

Navigating the Great Library and Murals

Once the connection is established, Evangeline's consciousness is transported into a Yithian body within the Pnakotus of the past. To solve the call of the elder gods observatory puzzle later, you must first gather data from the Great Library and the surrounding corridors. This area contains vital murals that represent different geological eras of Earth.

The Era Murals

  • 2nd Era: Features the Dimetrodon, a lizard-like creature from 270 million years ago.
  • 5th Era: Represents the age of Homo Sapiens, appearing roughly 300,000 years ago.

The Solar System Board

  • Located inside the library.
  • Identifies Earth as the third planet from the sun.
  • Provides the specific circular symbol for Earth used in the Central Map.

You must interact with every document on the desks within the library. There are three documents on the main central desk and three additional notes in the side alcoves. These notes explain the Yithian technology based on mirrors, light, and celestial alignment.

Era NumberRepresentative CreatureYithian Notation
Era 2Dimetrodon / LizardTwo wavy lines
Era 3Mammoth / PlioceneThree wavy lines
Era 4Tyrannosaurus RexThree wavy lines + Dot
Era 5Human / Present DayTwo wavy lines + Top Ball
Mural Importance

The murals are not merely decorative; they serve as the chronological key for the Central Map. You cannot progress to the observatory without identifying which era corresponds to the lizard-like creature seen in the prologue dream.

Call of the Elder Gods Observatory: The Constellation Puzzle

The call of the elder gods observatory is reached by taking the light path (yellow strand) from the upper level of the Great Library. This room features a massive domed ceiling decorated with various star patterns. Your objective here is to find the coordinates of Pnakotus in the current era (the era of humans).

1

Identify the Constellation

Look through the telescope to view the night sky. Compare the star pattern you see with the sketches in Evangeline's journal. One specific constellation will match her visions.

2

Note the Symbol

Directly underneath the matching constellation on the ceiling is a Yithian symbol. This symbol represents the specific sector of space for Pnakotus.

3

Determine the Planet

Refer back to your library notes. Earth is represented by a large circle with two wavy lines crossing through the center and a smaller circle positioned above them.

4

Calculate the Era

Since Evangeline is looking for the "present" Pnakotus, you must use the symbol for the 5th Era (Humanity).

Puzzle ElementRequired InputVisual Description
Planet SelectionEarthCircle with 2 waves and a small orb
Era Selection5th EraTwo wavy lines with a ball on the top end
ConstellationSector 8Large circle, 2 waves left, small orb right
Common Mistake

Many players confuse the 2nd Era (Dimetrodon) with the 5th Era (Human). You need the 2nd Era to find the past Pnakotus, but the 5th Era is required to generate the coordinates for the present day location.

The Central Map and Yithian Number System

After gathering the symbols from the observatory, return to the Central Map (the constellation machine). This device bridges the gap between the library's data and the ship's navigation system. You must input the planetary symbol for Earth and the numerical era.

The Yithian number system is based on a grid of lines and dots. Understanding this logic is essential for inputting the final coordinates into the Great Engineer's vessel.

Decimal NumberYithian Components
1, 2, 3Represented by 1, 2, or 3 horizontal lines.
4, 5, 6Base lines (1, 2, or 3) plus one dot.
7, 8Base lines plus two dots.
9Three base lines plus three dots.

Once you input the 5th Era and the Earth constellation into the Central Map, the machine will display the final navigation coordinates: 8, 9, 3, 4, 5.

Chapter 5 Completion Checklist:

  • Synchronize brainwaves with the Great Engineer (A3, B1, C4, D3)
  • Locate the 5th Era mural in the Great Library
  • Identify the Earth symbol from the Solar System board
  • Match the constellation in the Observatory
  • Input coordinates 89345 into the vessel's console
Coordinate Entry

When entering 89345 into the ship's autopilot, refer to the line-and-dot grid. For example, '8' is three lines with two dots, while '9' is three lines with three dots.

The Future and the Mind-Swapping Device

After launching the vessel, the scene shifts to the year 2006. Evangeline wakes up in a futuristic version of the facility, strapped to a mind-swapping device. This final puzzle of Chapter 5 requires reconnecting a series of wires to restore the consciousness link.

The Wire Solution: The device features a brain-like core with multiple sockets. You must experiment with the plugs until both indicators turn green. Based on successful gameplay patterns:

  • Connect the top-left plug to the center-right socket.
  • Connect the bottom-right plug to the top-middle socket.
  • Ensure all cables are seated until the yellow "deduction" lights turn into solid green "match" lights.
Device StateIndicator LightAction Required
IncorrectRed / No LightSwap wire positions
Partial MatchYellow LightOne wire is correct; keep it
CorrectDouble GreenProceed to the chair
The Final Choice

Upon returning to her body in the present, you will encounter Doctor West. He reveals a dark truth about the necessity of sacrificing Evangeline to stop Bowen. You must choose whether to tell Harry the truth or lie. This decision impacts the narrative tone leading into the final chapter.

For more detailed lore on the Yithians and the Starry Wisdom Society, you can check the official Call of the Elder Gods Steam Page for developer updates and community guides.

FAQ

Q: How do I find the Earth symbol for the call of the elder gods observatory puzzle?

The Earth symbol is located on a diagram of the solar system found on a board inside the Great Library. It is identified as the third planet from the sun and is represented by a circle with two wavy lines through it and a small circle above.

Q: What are the coordinates for the Great Engineer's spaceship?

The coordinates are 8, 9, 3, 4, 5. These must be entered into the vessel's navigation console using the Yithian number system of lines and dots.

Q: Why won't the Central Map accept my era input?

Ensure you are using the 5th Era (Humanity) symbol if you are trying to reach the present-day Pnakotus. Using the 2nd Era (Dimetrodon) will only show you the past version of the city.

Q: Where is the screwdriver needed for the Chapter 4 power puzzle?

Although Chapter 5 focuses on the observatory, if you are stuck in Chapter 4, the screwdriver is located on the table right next to the fuse box in the radio station.

Call of the Elder Gods Observatory: Chapter 5 Puzzle Walkthrough - Call of the Elder Gods Wiki