Power Behind the Pulpit Achievement
Power Behind the Pulpit10
Read Sybil’s journalDuring the Werewolf's chapter, follow the story until you meet with Essex and Cleric Franciscus in Absolution Hall. After this conversation, you will be able to find the journal (it doesn't seem to spawn until this point). Move the curtain in this office and press the button on the wall to move a statue and gain access to the basement. Then, use a Lightning in a Bottle to electrify the door into opening. Read the journal to unlock the achievement. Sybil and everyone else here will become hostil, so if you want to avoid a fight you can save prior and just reload and leave it alone, though it doesn't hurt any achievements to kill everyone either.