"Okay", Mystery Man reluctantly agreed: "I will do you a favor. But first tell me where I can find my brother."
The Green Entity chuckled and said: "Good luck, Mystery Man: your Brother is being held in a tower which is neither in this world nor the next, and is both tangible and intangible until the silver blood moon strikes upon it."
"Okay, and how do I get there?" Mystery Man asked.
"That is not for us to tell, we would only tell you where your brother is. Now it is time for you to return the favor."
A horde of creatures appeared on the horizon. All looking eagerly in anticipation. Saliva drooling from their little, thin mouths. "We now shall have your fondest memory from the time of your childhood, which hides in the deepest recesses of your soul, Mystery Man. Hand it over, per our agreement."
"You tricked me!" Mystery Man shouted. The entities approached silently and, undisturbed, they drew ever closer.
In the corner of his eye, Mystery Man suddenly saw, to his rescue: almost hidden in shadow behind a large and gnarled old tree, a small elf-like creature. This creature, he saw, had but one eye but it moved rapidly closer, and to Mystery Man's surprise in one fist it held a bunch of licorice sticks. And then it stopped, opened its mouth, and ....
:)