Which version this walkthrough covers
The clearest written sequence comes from SECOND's illustrated September 2023 demo playthrough. Independent Steam replies support the chemical, blood and sunlight connection, including the iron clue associated with blood. These sources support an opening solution, rather than a claim that the final campaign follows an identical route.
Later demos changed during development, as the official demo v0.4 announcement demonstrates. That history makes a version comparison essential when a room, object or interaction differs from an older guide. Do not interpret such a difference as proof that you have missed an undocumented secret step.
Prepare the glass and developing chemical
Collect the glass and the developing chemical before attempting to finish the sealed-door sequence. The historical written account shows these objects being combined rather than used as separate answers at the door. If your build presents different objects, stop and compare its own clues before continuing with this old route.
- Find the glass in the historical opening sequence.
- Collect the developing chemical.
- Combine the glass and chemical through the inventory.
- Take the filled glass to the bloody bathroom mirror.
The supplied evidence does not establish a current-build item-location map. It would therefore be misleading to add precise room coordinates or a new navigation route around these steps. For general inventory handling rather than the puzzle answer itself, see the beginner tips.
Use the bloody mirror and the sunlight
Use the filled glass at the bloody bathroom mirror in the documented puzzle. Players in the collected Steam discussion connect blood with the iron clue, while the illustrated account corroborates the bathroom interaction. Their wording is not fully identical, so this guide retains the shared interaction without inventing an additional substance or action.
The next documented stage involves the window and its light. Use the wrench to remove the lower window board, then expose the mixture to the sunlight. Apply the prepared mixture to the red seal at the blocked door to finish the recorded opening solution.
What to do when your room does not match
Check the build and the visible puzzle clues before repeating an older sequence. Demo v0.4 also documented the requirement to face an object when interacting, which can help explain a failed action in that particular version. That rule is a build-specific interaction detail, not a guarantee that every apparent blockage has the same cause.
The demo guide links official download options and explains the video references. The combat guide deals separately with the wrench and revolver patch evidence. Neither guide substitutes a historical demo endpoint for a complete ending route, which is addressed in all endings.