The Phantom Tollbooth
"You will, of course, need a guide," said the king, "and, since he knows the obstacles so well, the Humbug has cheerfully volunteered to accompany you."
"Now see here," cried the startled bug, for that was the last thing in the world he wanted to do. (8.66-67)
All the flowers suddenly appeared black, the gray rocks became a lovely soft chartreuse, and even peacefully sleeping Tock changed from brown to a magnificent ultramarine. Nothing was the color it should have been, and yet, the more he tried to straighten things out, the worse they became.
"I wish I hadn't started," he thought unhappily as a pale-blue blackbird flew by. "There doesn't seem to be any way to stop them." (11.12-13)
"You must visit the Soundkeeper and bring from the fortress one sound, no matter how small, with which to load our cannon. For, if we can reach the walls with the slightest noise, they will collapse and free the rest. It won't be easy, for she is hard to deceive, but you must try." (12.47)