Make Aurisatio with developing chemical, Julia's blood and sunlight to open the studio and enter the Desiderium. Ivan's apartment is the first stop in Tenebris Somnia: apartment B on the third floor, opened with Julia's own key.
How do you enter Ivan's apartment?
Take the elevator to the third floor and use the apartment key on apartment B. Julia is too tired to use the stairs, so head for the elevator instead.
At B, knocking gets no response. Open your inventory, select the apartment key and use it to enter.

What is the Aurisatio recipe?
The Aurisatio recipe is developing chemical containing tartaric acid, Julia's blood for iron, and sunlight, mixed in the bedroom's empty glass. The old book on the bedroom floor explains that Aurisatio dissolves the red Desiderium seal.

Take the bathroom wrench
Pick up the heavy wrench in the bathroom. You'll need its weight to break the loose wood covering the bedroom window.

Collect the refrigerated developing chemical
Open the kitchen refrigerator and take the developing chemical. Its inventory description lists tartaric acid, which supplies the acid in the recipe. The chemicals in the bathroom are a distraction here: Julia refuses to touch those.


Open the bedroom window to sunlight
Use the wrench on the loose boards covering the bedroom window. The lower wood breaks away, letting sunlight fall onto the floor. This gives you the light needed to finish the mixture later.

Fill the empty glass
Take the empty glass from the bedside table to the left of the bed. In your inventory, combine it with the developing chemical to make a glass with chemical.

Add Julia's blood at the broken mirror
Return to the bathroom and interact with the broken mirror with your prepared glass. Julia cuts herself on the broken glass and adds her own blood, supplying the iron the recipe needs.

The blood already on the mirror is dry and cannot be put into the glass. Julia's own blood completes this ingredient; don't keep trying to collect the old stain.
Expose the mixture to sunlight
Go back to the bedroom and use the mixture at the opened window. The liquid changes to a strange color and releases a lot of heat. You now have Aurisatio.

How do you remove the red seal on the studio door?
Use the finished Aurisatio on the hard red substance sealing the studio door. It dissolves, allowing you to enter the Desiderium through the studio.

The door's coating looks like very hard red wax. The old book calls the sealing layer lapis fictus, which is why preparing its solvent gets you through.
What should you do inside the studio?
Save at the emerald flame, read Ivan's note and pick up the green candle from the floor before leaving.

Ivan's note directs him to take the elevator to the lowest floor. Read it for your next destination, then collect the green candle by the back wall.


With the studio seal dissolved, your progress saved and the green candle collected, leave the apartment and continue with the Tenebris Somnia second floor walkthrough.