Now they were right up to the crack in the black mountain - so close they could touch it.

Next moment they were inside - and they could hardly believe what they could see!

It was a forest. A green, green forest. Huge trees, with strange red trunks and shiny blue and green leaves, stood above them, towering over the three friends like huge skyscrapers.

Sweet-smelling bushes with strange spiky yellow and green leaves were all around, waving gently in the warm breeze that warmed the forest.

The bright light had gone. Instead, warm sunrays shone through onto the forest paths, slowly moving away as they came near, but always there.

Dot tried to put her hand into one of the sunrays, but it just gently curled round her arm, and then slipped away.

She tried to follow it, but it moved away again, always just in front of her, never close enough to catch. It made a kind of singing, laughing noise as it went, as if it was a game they were playing - a game it couldn't lose, called 'Catch The Sunray'!

Wizzie joined in, jumping up and trying to grab them in his mouth. They just danced away from him too. Even Mr Mouse - who'd got over being scared - made a grab at one of them, but he missed too. Only one, because he nearly fell off Dot's shoulder as he tried!

But the strangest thing of all was the books!

Millions and millions of them everywhere you looked. It was like a library, only a very strange library - not like one Dot had ever seen before.

Because wherever she turned, there always seemed to be more of them - you only had to turn your head towards them and suddenly new ones would appear... lying on shelves in the trees, piled up beside the soft sandy paths they were walking along, even hanging like fruit from the branches of the strange red trees.

The books were all very posh - made out of a kind of leather, in lots of different colours, red and dark blue, black and dark green. They all had gold patterns and decorations on them, and the edges of the pages were gold too.

Well, you know, Dot loves reading, it makes her feel like she's in a world of her own, one that she's making in her own mind as she reads... so, of course, she had to reach out and take one down, only for a quick look so she could see what it was all about.

But just as she did so, a really strange thing happened - suddenly, Wizzie snapped and growled, backing away from her, his tail tucked between his legs.

"Don't, Dot!" he said. "Don't! PLEASE don't! DON'T"

Too late! Much too late!