The Ice Garden — Guy Jones

Jess's imagination has always been her best friend. She's trained it to feel as real as it possibly can, especially in the stories she writes for Davie -- the young boy in a coma who is her only friend. But nothing is as real as the world she'll find.

One night, tired of peeking at the other children beyond her curtained house, she sneaks out to explore the empty playground she's longed to visit. Beyond, she discovers a garden made entirely of ice. This is her place: a Narnia with flying elephant mice and ice apples with shining gold liquid inside.

But Jess soon discovers that she's not alone. And her presence there could be destroying its very existence.