Emma wasn't too sure.

Just then, a slow-moving, matronly white Cloud Ship with sails full of sweet-scented wind came drifting by.

"Come on!" invited the puff clouds. "Let's take a ride."

So Emma climbed on board, waved good-bye to the Starcatcher, and off they sailed with a blue sky swelling below them like an ocean. Emma stood at the bow of the ship and let the sweet-scented wind blow her hair. The puff clouds bounced and tumbled on and off and all around the ship, escorting it like a fleet of playful dolphins.

They sailed over a mat of glossy, mounded clouds with curling peaks.

"Oh, they look like whipped cream!" exclaimed Emma.

They sailed through a lemon-lime curtain of mist, and slid down a lavender cloud that unfurled like a scarf. Emma was laughing and enjoying herself so much that she had completely forgotten all her bruises, when suddenly a shadow darkened the sky, a bolt of lightning crashed, and a roll of thunder made the air tremble like the surface of a drum.

All the little puff clouds squealed and scurried to hide in the shadow of the big white motherly Cloud Ship.

"You!" boomed the voice of the thunder.

Emma jumped. "Who's that?" she whispered. Another bolt of lightning crashed, and the thunder rolled again, "You puff clouds!"

The dark sky heaved and rolled like an ocean wave tossed in a tempest. "It's the Cloud Prince," whispered one of the puff clouds, "and he's not in a very good mood."

Emma felt the ship being blown along by a fast, feverish wind. An army of stern-looking metal-gray clouds gathered to speed along behind it. The puff clouds clung to the sides of the ship, their rounded puffs blown out of shape into thin, cottony trails.

When they came to a stop, the puff clouds fluffed themselves and fluttered around Emma. They stood at the foot of a soaringly tall and majestic Cloud Throne. Its pewter turrets and ebony spires rose into the sky so high they almost reached out of sight, and the Cloud Prince himself loomed over their heads like the biggest, blackest storm cloud Emma had ever seen. He fumed and he swelled and he grew and he changed his shape. He became a giant black vulture with a drooping, menacing neck that twisted back and forth like a snake. He spread his wings and held them out, and they reached across the whole breadth of the sky. Then he swelled and he grew and he changed his shape again, becoming a green-scaled dragon with long sharp claws of glinting steel, and a flaming tongue that lashed all around like a whip.

"What's he going to do to you?" whispered Emma to the nearest puff cloud.

"I don't know," she whispered back. "His moods are very changeable."

The Cloud Prince swelled and he grew and he changed into the shape of an enormous black bear with fur that bristled like a porcupine's quills and a cavernous mouth full of teeth that snapped like lightning.

"Someone has stolen my Silver Lining," he grumbled in a low, threatening way.

"I beg your pardon, sir," said one little puff cloud.

"My Silver Lining," he grumbled and rumbled, and his teeth like lightning crackled and snapped. "Someone has stolen my Silver Lining, and I want to have it back!"

"But we don't have it," said the little puff clouds all together.

"Don't waste my time!" the Cloud Prince roared, rising up on his two back legs. His black fur bristled, and he hurled a sizzling bolt of lightning at them. "You mischievous puff clouds are always causing some kind of trouble around here, and if you don't find my Silver Lining soon, I'm going to roll you all up into little balls and throw you into the fires of the sun!"

The poor little puff clouds all squealed and whimpered and tried to hide again in the skirts of the motherly Cloud Ship. But the angry Cloud Prince swelled and he grew and he changed again into a fierce black-speckled dog with long lean legs and sharp red eyes, and he looked ready to come after them for sure. Emma was very much afraid for them. Besides - she thought she knew something that could help.

"Wait!" she cried. "Don't hurt them, please. I think I know where your Silver Lining might be."

"You?" the Cloud Prince barked. "Where did you come from? And how could you know anything at all?"

"I came from down on the earth. And I saw it last night," she said. "It was after a storm that passed over the little brick house in the country where I live. I looked out the window to show my baby brother that the storm was gone, and we saw it - a big dark purple cloud with a gleaming silver lining. It was floating just over the treetops on the western horizon, and I'll bet it got caught there, in the branches of a tree.

"Then what are you waiting for," snarled the Cloud Prince. "Go and get it for me!"

"But . . . but I can't go by myself," said Emma. "I don't know how, and I can't fly."

The Cloud Prince swelled and he grew and he changed his shape again, becoming a ferocious, snorting black bull. He struck blood-red sparks in the air with his hooves.

"Don't waste my time!" he bellowed.

"Come on!" twittered the little puff clouds anxiously. "We'll take you."