The palace's interrogation room was located on the level just above the deepest, darkest part of the palace's underground dungeon. This area reeked from all the spells and enchantments that were placed all over the cave-like room. The vampires somehow managed to have a witch cast a spell in this particular room so that no other witches could see what was going on inside it.
Witches were loyal creatures. They would rather kill themselves than betray their kind, especially their queen. That was why it was almost impossible for vampires to force any of them to speak or do something that might hurt their kind.
