Room can be Dark. Dark is a synonym of Hidden. 
you are likely to find Organ in/at/on Animal. Adult is a type of Animal. Researcher is a type of Adult. Analyst is a type of Researcher. 
Room --HasProperty--> Dark <--Synonym--> Hidden 
Organ --AtLocation--> Animal <--IsA-- Adult <--IsA-- Researcher <--IsA-- Analyst 