The Palace of Wisdom is a library. Inside, there are a million books. No-one knows who wrote them. Only a few people come here to read. I was there one day and suddenly wondered, 'Why are there no authors for these books? Or, if there were authors, why did they leave their names off the books?' Then a voice replied, 'These authors bargained with me, and I gave them their true desires on the condition that they hid their faces.'