"After having seen this," said the Sultan, "I cannot rest. These fish signify some mystery I must clear up."
He sent for the fisherman. "Fisherman," he said, "the fish you have brought us have caused me some anxiety. Where did you get them from?"
"Sire," he answered, "I got them from a lake which lies in the middle of four hills beyond yonder mountains."
"Do you know this lake?" asked the Sultan of the grand-vizir.
"No; though I have hunted many times round that mountain, I have never heard of it," said the vizir.
As the fisherman said it was only three hours' journey away, the sultan ordered his whole court to mount and ride thither, and the fisherman led them.
They climbed the mountain, and then, on the other side, saw the lake as the fisherman had described. The water was so clear that they could see the four kinds of fish swimming about in it. They looked at them for some time, and then the Sultan ordered them to make a camp by the edge of the water.
When night came the Sultan called his vizir, and said to him, "I have resolved to clear up this mystery. I am going out alone, and do you stay here in my tent, and when my ministers come to-morrow, say I am not well, and cannot see them. Do this each day till I return."
The grand-vizir tried to persuade the Sultan not to go, but in vain. The Sultan took off his state robe and put on his sword, and when he saw all was quiet in the camp he set forth alone.
He climbed one of the hills, and then crossed the great plain, till, just as the sun rose, he beheld far in front of him a large building. When he came near to it he saw it was a splendid palace of beautiful black polished marble, covered with steel as smooth as a mirror.