Prologue

One summer day in Frog Creek, Pennsylvania, a mysterious tree house appeared in the woods.

Eight-year-old Jack and his seven-year-old sister, Annie, climbed into the tree house. They found it was filled with books.

Jack and Annie soon discovered that the tree house was magic. It could take them to the places in the books. All they had to do was to point to a picture and wish to go there.

Jack and Annie visited dinosaurs, knights, an Egyptian queen, pirates, ninjas, and the Amazon rain forest.

Along the way, they discovered that the tree house belonged to Morgan le Fay. Morgan was a magical librarian. She traveled through time and space, gathering books for King Arthur’s library.

On their fifth adventure, in Night of the Ninjas, Jack and Annie found a little mouse in the tree house. Annie named their new friend “Peanut.” Jack and Annie also found a note from Morgan. The note told them that she was under a spell. To free her, Jack and Annie must find four special things.

They found the first thing in old Japan, and the second in the Amazon rain forest.

Now Jack and Annie and Peanut are about to set out in search of the third thing … in Sunset of the Sabertooth.

1. The “M” Things

“Let’s go to the tree house,” said Annie.

She and Jack were passing the Frog Creek woods on their way home from their swimming class at the Y.

“No. I want to go home and change out of my bathing suit,” said Jack.

“Oh, that’ll take too long,” said Annie. “Don’t you want to save Morgan as soon as possible?” “Of course,” said Jack.

“Then come on! Before the sun sets!” said Annie.

She darted into the woods.

Jack sighed. He gave up on the idea of changing out of his bathing suit.

He pushed his glasses into place. He followed Annie into the Frog Creek woods.

The warm air smelled fresh and green.

He moved through patches of sunlight and shadow. Soon he came to a small clearing.

He looked up. There it was. The magic tree house in the tallest tree in the woods.

“Hurry!” called Annie. She was climbing the rope ladder up to the tree house.

Jack grabbed the ladder. He started up after her.

Finally they reached the tree house.

Squeak. A mouse sat on the window sill.

“Hi, Peanut!” cried Annie.

Jack patted the tiny head.

“Sorry we didn’t come sooner,” Annie said. “But we had to go to our swimming lesson.” Squeak.

“What happened while we were gone?” asked Annie, looking around the tree house.

Jack stared at the large M carved into the wooden floor.

On the M were a moonstone and a mango, the special things they’d found on their last two journeys.

“Hey, guess what?” said Jack. “Moonstone and mango start with the letter M. Just like Morgan.” “You’re right,” said Annie.

“I bet all four things start with an M,” said Jack.

“Right,” said Annie. “I wonder where we’ll find the next one.” She and Jack stared at the stacks of books in the tree house. Books on the Amazon rain forest, ninjas, pirates, mummies, knights, and dinosaurs.

All of them were closed. Only one book lay open in the corner.

“We’re just about to find out,” said Jack.

They walked over to the open book.

They looked at the page the book was opened to. It showed a picture of rocks and snow.

“Wow,” said Annie, running her finger over the picture. “I love snow. I wish we could go there right now.” “Wait,” said Jack. “We’re not prepared.” Then he had another thought. “And we’re wearing our bathing suits! Stop!” “Oops,” said Annie.

Too late. The wind started to blow.

The leaves started to shake.

The tree house started to spin.

It spun faster and faster!

Then everything was silent.

It was as silent as the falling snow.

2. Bones

Jack, Annie, and Peanut looked outside.

Snow was falling from a gray sky.

The tree house was in the tallest tree in a grove of tall, bare trees.

The grove was on a wide, white plain. Beyond the plain were high, rocky cliffs.

“I’m c-cold,” said Annie. Her teeth chattered. She wrapped her towel tightly around her.

Sq-squeak. Peanut sounded cold, too.

“Poor mouse,” said Annie. “I’ll put you into Jack’s pack. You’ll be warmer there.” Annie slipped Peanut into the pocket of the backpack.

“We have to go home,” said Jack. “We need warmer clothes.” “We can’t go home,” said Annie. “We can’t find the Pennsylvania book. Not until our mission is complete. Remember? That’s the way the magic works.” “Oh … right,” said Jack. He looked around. There was no sign of the Pennsylvania book that always took them home.

Annie peered out the window again. “Where are we, anyway?” she asked.

“I’ll find out,” said Jack. He picked up the open book and read the title on the cover. “Life in the Ice Age.” “Ice Age?” said Annie. “No wonder we’re cold.” “We better find the third M thing soon,” said Jack. “Before we freeze to death.” “Look,” whispered Annie, “people.” She pointed out the window.

Jack saw them, too: four figures on a cliff. Two big figures and two little ones—all holding long spears.

“Who are they?” said Annie.

“I’ll look in the book,” said Jack.

He found a picture of some people. He read the caption to Annie: Early modern humans were called Cro-Magnons. During the late Ice Age in Europe, they sometimes lived in caves beneath cliffs.

“Why are they carrying spears?” said Annie.

Jack turned the page. He found another picture of the Cro-Magnons. He read aloud: The Cro-Magnon family often hunted together. They covered deep pits with branches. Then they drove reindeer and mammoths into the traps.

“Oh, trapping the animals—that’s sad,” said Annie.

“No, it’s not,” said Jack. “They couldn’t live without hunting. They didn’t have supermarkets, you know.” They watched the family disappear over the other side of the cliff.

“Come on, I’m freezing,” said Jack. “Let’s hurry and find the M thing while the Cro-Magnons are hunting.” “But I want to meet them,” said Annie.

“Forget it,” said Jack. “They don’t have books that tell them about us. They’ll think we’re some enemy and hurl their spears.” “Yikes,” said Annie.

Jack put his book away.

Squeak. Peanut peeked out of the backpack.

“Stay in there,” said Annie.

Jack pulled on his pack and started down the rope ladder.

Annie followed.

On the icy ground, they huddled together.

The wind was biting. Jack put his towel over his head. Snow blew against his glasses.

“Hey, Jack,” said Annie. “Look at me.” Annie had put on her swimming goggles. “Now I can see,” she said.

“Good thinking,” said Jack. “Now cover your head with your towel. Most of your body heat is lost through your head.” Annie wrapped her towel around her head.

“We should find a cave or someplace warmer,” said Jack.

“I bet there are caves in those cliffs,” said Annie.

She and Jack started across the white plain. The snow wasn’t deep yet. But the wind was blowing hard.

“I told you!” Annie pointed to an opening in the rocks—a cave.

They ran to it.

“Careful,” said Jack. They stepped carefully into the shadowy cave.

It was only slightly warmer inside. But at least the wind wasn’t blowing.

In the gray light, they stamped the snow off their sneakers.

Annie took off her goggles.

“It smells in here,” said Jack.

“Yeah, like a wet dog,” said Annie.

“Let me see what I can find out,” said Jack.

He pulled out the Ice Age book.

“I’ll look around,” said Annie. “Maybe the M thing is here. Then we can go home and get warm.” Jack stood by the entrance so he could read the book.

“This cave is filled with sticks,” Annie said.

“What?” said Jack. He didn’t look up from the book.

“No, wait. I think they’re bones,” said Annie.

“Bones?” echoed Jack.

“Yeah. Lots of them back here. All over the floor.” Jack turned the pages of his book. He found a picture of a cave filled with bones.

“I hear something,” said Annie.

Jack read the writing below the picture of the cave. It said: The great cave bears of the Ice Age were over eight feet tall. These bears were larger and fiercer than today’s grizzlies. Their caves were filled with the bones of their ancestors.

“Annie!” whispered Jack. “Get back here now!” They were in the cave of a great cave bear!

3. Brrr!

“Annie!” whispered Jack again.

No answer.

He put his book quietly into his pack. He stepped deeper into the cave.