Prologue TheCrystal Keeper gazed up at the diamond-- which was now the size of an acorn--marvelling at the two blurry shapes inside. As he stared he noticed something that didn't look quite right. Just under the icy surface was an unmistakable dark streak. 'Oh no,' he whispered, 'an impurity!' His heart started to hammer as he got out his magnifying glass for a closer look. This had never happened in a royal diamond before. What did it mean? He would have to inform the authorities right away. There was much debate in Wiskling Wood about what was to be done. 'It's impure,' said Lord Astrophel.

'The twins inside cannot be true royals.' 'But it's still a diamond,' argued a handful of the other high authority members. 'And they don't come along very often.' But as the crystal grew the mark got bigger and darker until it looked like there was a long black stitch running right through the middle of it. Lord Astrophel declared it a bad omen and soon almost everyone agreed with him. On the fateful night the diamond cracked there was a terrible storm. Outside the Crystal Cave the sky was dark and blotchy as though someone had splashed a pot of violet ink all over it. Fat drops of rain sploshed to the ground and a huge cherry pink moon hung down over the wood, casting an eerie glow over the trees.

Thunder began to rumble and the cave lit up suddenly with a flash of lightning. All the crystals sparkled with a ferocious light. The cave lit up again, another deafening rumble of thunder roared across the sky, and the diamond split right open. The Crystal Keeper leapt forward to catch the two babies that fell out one after the other in a shower of twinkling jewel dust, and stepped back to avoid the shards of diamond falling to the floor. He looked down at the two bundles in his arms and was shocked to see the difference between them. The second twin was small and sweet with faint wisps of silvery blonde hair and long eyelashes sticking out from the corners of her eyes like whiskers, indicating she was a girl. The one who had fallen first also had long eyelashes but her skin was as pale as ice and her hair a sooty black. Instead of a contented smile this baby was scowling.

The Crystal Keeper gazed around at the shards of impure diamond crystal glittering furiously on the floor, and shivered with a terrible sense of foreboding.