Where are the switches?
I presume you have already been in the locked room in the library, and found the scroll. Okay. The “keystone” is in the garden (go to the eastern wall, and raise your head). The “Brother Mason” is dead and so he is on the graveyard. The “St. Yora” is in the reliquiary. The “kitchen” is now the loot collection in the basement. The “rack” is in the Inquisitor’s torture chamber.