"But how beautiful! What colours! Where will it stop? It is more like the rainbows you can tread on. More like dreams."
The colour and the sound grew together. The rainbow spanned an enormous gulf. Clouds rushed under it and were pierced by it, and still it grew, reaching forward, conquering the darkness, until it touched something that seemed more solid than a cloud.
The boy stood up. "What is that out there?" he called. "What does it rest on, out at that other end?"
In the morning sunshine a precipice shone forth beyond the gulf. A precipice—or was it a castle? The horses moved. They set their feet upon the rainbow.
"Oh, look!" the boy shouted. "Oh, listen! Those caves—or are they gateways? Oh, look between those cliffs at those ledges. I see people! I see trees!"
"Look also below," whispered Sir Thomas. "Neglect not the diviner Acheron."
The boy looked below, past the flames of the rainbow that licked against their wheels. The gulf also had cleared, and in its, depths there flowed an everlasting river. One sunbeam entered and struck a green pool, and as they passed
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