✦ Craft & Quest

Tenebris Somnia · Ivan’s apartment

How to open the sealed study door in Ivan’s apartment

On this page
  1. Collect the three tools before mixing anything
  2. Open the window and prepare the mixture
  3. If the door still refuses the item
  4. Sources and version

Make Auritsatio: use the Glass at the broken bathroom mirror, combine the resulting Glass with Blood with Developing Chemical, then use the mixture in the bedroom sunlight. Take the finished item back to the study door.

Published October 20, 2026 · Full PC release · Puzzle spoilers for this section

Ivan’s apartment living room with the blue bathroom door, grey kitchen door and sealed study door
The blue door beside the Devora poster leads to the bathroom. The grey door beside it leads to the kitchen; the marked study door is your eventual destination. Source: Developer’s Official Puzzle & Boss Guide. Game © Andrés Borghi / Saibot Studios / New Blood Interactive. Select for the full image.

Collect the three tools before mixing anything

These are separate inventory items. Keep the Wrench equipped when you reach the boarded bedroom window; simply carrying it does not remove the boards.

Open the window and prepare the mixture

Bedroom in the official Tenebris Somnia walkthrough showing the nightstand Glass and boarded window
The Glass is on the nightstand to the left of the bed. The boarded window is on the right. Break the lower board with the Wrench so sunlight can enter. Source: Unmutual’s demonstration linked by the developer, 1:17. Game © Andrés Borghi / Saibot Studios / New Blood Interactive. Select for the full image.
  1. Attack the window boards with the equipped Wrench until the lower board falls and sunlight is exposed.
  2. Take the Glass and return to the bathroom.
  3. Stand in front of the broken mirror and choose Use on the Glass. Check that the item becomes Glass with Blood.
  4. Choose Combine to mix Glass with Blood and Developing Chemical.
  5. Return to the opened bedroom window and use Glass with Chemical and Blood in the sunlight.
Julia standing at the broken mirror on the right side of Ivan’s bathroom
The mirror on the right is the Glass interaction point. Check the item’s name afterwards before leaving for the bedroom. Source: Unmutual’s demonstration linked by the developer, 1:32. Game © Andrés Borghi / Saibot Studios / New Blood Interactive. Select for the full image.

If the door still refuses the item

Inspect which stage you are carrying. Plain Glass needs the mirror step. Glass with Blood still needs Developing Chemical. Glass with Chemical and Blood still needs sunlight. The item used at the study door is the finished Auritsatio.

If the mixture does not change at the window, check that you removed the board and are standing at the exposed light. Clicking Combine in the inventory does not perform this location-specific Use action.

Once the finished item appears, return to the sealed study door and use it there. This completes the opening apartment chain; the later television puzzle needs its own batteries and a trip between floors.

Sources and version

Checked October 20, 2026 against the developer’s official guide, Door Puzzle in Ivan’s Apartment and its linked Unmutual video walkthrough. Screenshots are limited instructional excerpts from those sources, not our own playthrough. Official 1.0.1 patch notes.

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