Pinhead- Thrall Mentality

 Then the Hell Priest quickly scrawled something upon the air, leaving a few black characters in front of him. “I’m unlocking the restraints I put on your memory.”

  “Re … traints?”

  “Of course. Without them, you would have gone mad long ago. But I have need of your assistance. There. A small part of what you knew has been restored. Use it sparingly, and in my service, and I will reward you with more, by increments.”

  A few narrow doors had suddenly opened in Felixson’s head, each one a book, its contents a piece of his power. The knowledge brought with it a tiny piece of his history and he was suddenly mortified at his state.
...
  “The gift is most welcome, Master,” he said, finding that the power to form a coherent sentence had also been restored. Whether it was on purpose or an unintended side effect of his master’s working, Felixson knew not, but he knew enough not to question it.

  “Remember that,” said the Hell Priest.

  “Of course. Your generosity—”

  “Not the gift, Felixson. Master. Remember my name. Forget it for an instant and I’ll wipe you clean. You won’t even remember to crouch when you shit.”

  “Yes, Master.”

  As he trembled, his mind filled with doors opening and closing in howling winds that had sprung up from compass points he could not even name, and in those winds came words and phrases arbitrarily loosed from the remembered pages.

-The Scarlet Gospel, BOOK TWO, Chapter 9