"Pass me the blue one." said Quinn.
"Are you sure?" asked Elise. "It's just, you were sure about the last two combinations, and that ceiling got closer both times."
"It's a gamble, I agree," replied Quinn, "but whatever's behind this door has got to be worth it."
Elise passed Quinn the blue stone which he placed carefully in the final slot. As the grinding began, Quinn looked to the door while Elise looked up...
A world where, instead of aging in years, the people age in knowledge. So, instead of dying once a general age was reached, they die once they achieve a certain amount of knowledge. A man could live forever if he never learned anything, or could die after reading a few choice books. Of course, the knowledge of the land would be regulated, like medical drugs.