The guards turned upon Ferdâsan, who stood calm and unmoved, looking at the King. Then, as they were about to seize him, a strange thing happened. They clutched at the empty air and staggered against one another, amazed. For a moment the Throne-room seemed to echo a sweet music from far away; for a moment it was filled with the faint fragrance of mountain lilies; then the King saw a thin grey mist slowly issuing through one of the windows, to dissolve in the sunlight.

From that time forward, the King regarded the seer's prediction with great anxiety. He watched the young Prince continually in his first years, and, when, as was often the case, he saw him gazing wistfully towards the west when the sun had set, he felt sure that the coming event had cast its shadow before.

Edmund Dulac’s Fairy-Book — Part 120

Accordingly, as soon as the young Prince entered his fifteenth year, the King had him imprisoned in a lofty tower situated in the palace gardens, and placed a guard about it, for he was determined to take no risk whatever.

Edmund Dulac’s Fairy-Book — Part 120

But, while he kept the Prince a close prisoner, he surrounded him with every luxury, for he loved him dearly. He even promised him that, on his fifteenth birthday, a great festival would be held in his honour, though he himself would only be allowed to watch the festivities from the high window of the tower.

Edmund Dulac’s Fairy-Book — Part 120

The Prince implored his father to let him wander in the gardens on his birthday; but the King was so afraid that, by some means or other, he would be spirited away, that he refused. In addition to this, he double-locked and barred the topmost room of the tower in which the Prince was imprisoned.

On the day of the festival, the sun rose bright. As the Prince watched it from his high window, his heart rose with it. At noon he had fully decided to disobey his father and escape from his prison. He brooded till sunset; then, as the twilight gathered, he went to the window again and listened to the sounds of festivity in the city all around. Presently, he leaned out over the window-sill and looked down. It was a long way to the ground, but the gardens were beautiful, and he was determined to reach them and roam free among the trees and flowers. Was not this his birthday, and was not the city holding high festival in his honour? It seemed hard that he should be a prisoner, when even the guards of his prison had stolen away to join the merry throng. The city without was a blaze of light and a chorus of revel, but the gardens below seemed to be deserted: now was his opportunity.