Many of the inhabitants of the mansion didn't even have any idea about the existence of this room. It does not appear on the map or in the drawings of the house. Who and for what reasons used this room? - A question to which, alas, still no one can give an answer.
To enter this room you will need filters for the gas mask. (Read how to get them here) Going through the cellar you can find pages of the diaries of the Poisoned and the Poisoner and also of the Puppeteers' memoirs.
Available since level 25