At that moment, Harry fully understood for the first time why people said Dumbledore was the only wizard Voldemort had ever feared. The look upon Dumbledore‘s face as he stared down at the unconscious form of Mad-Eye Moody was more terrible than Harry could have ever imagined. There was no benign smile upon Dumbledore‘s face, no twinkle in the eyes behind the spectacles. There was cold fury in every line of the ancient face; a sense of power radiated from Dumbledore as though he were giving off burning heat.
- Harry Potter and the Goblet of Fire, J.K. Rowling