The dogs were barking wildly at two smallcreatures playing in the moonlight.

"Polar bear babies!" cried Annie.

One roly-poly cub leaped onto the other. Then theyboth rolled through the snow.

"Hi, little bears!" Annie called.

The cubs jumped up and shook themselves like wetpuppies. Then they scampered toward Annie, whorushed to greet them.

"Hi, hi, hi!" she called.

"Wait--" shouted Jack. "Where's their mother?"He looked around for the mother bear, but she wasnowhere in sight. Maybe the y re orphans, hethought.

Jack looked back at Annie. She was wrestling withthe little bears in the snow. She was laughing so hardthat she couldn't stand.

Jack started laughing, too. He carefully put the bearmasks into his pack. Then he ran to join Annie.

She was running with the cubs across the snowytundra. One of them raced to her, tagged her, thenraced away. Annie ran after the bear and tagged himback.

"You're it!" she said.

Jack and the other cub joined in. Soon Jack andAnnie and the two cubs were all chasing each otherover the moonlit snow.

They ran until the two cubs fell down ahead ofthem. The cubs lay perfectly still.

Panting, Jack and Annie stared at them.

"Are they hurt?" Annie wondered out loud.

Jack and Annie ran to the cubs.

Then, just as they leaned down to see if they wereall right, the cubs jumped up. They pushed Jack andAnnie over and scampered away.

"They were pretending!" said Jack. He laughed.

Jack and Annie charged after the cubs. They ranover the white tundra until they came to the frozensea.

Jack looked around.

"We're pretty far from the igloo. I don't hear thehuskies anymore," he said. "Maybe we should goback.""In a minute," said Annie. "Look!" The bear cubshad scooted up a snow bank.

They were on their backs, sliding down the bankonto the ice-covered sea.

Jack and Annie laughed.

"It's like sledding!" said Annie. "Let's try it!""Okay," said Jack, "but then we have to go back."Jack followed Annie up the snow bank. He clutchedhis pack in his arms.

Annie lay on her back. She whooped as she sliddown the ice.

Jack followed her.

"Watch out below!" he shouted.

The little bears were sitting at the bottom of thesnow bank. One gently whapped Jack in the face withher furry paw. Then she lay down.

"I'm tired, too," said Annie.

"Yeah," said Jack. "Let's rest for just a minute."Jack and Annie looked up at the orange moon asthey lay beside the cubs. All they could hear was thewind and the soft breathing of the cubs.

"That was fun," said Annie.

"It was," said Jack. "But we'd better head back to theigloo. The seal hunter's probably looking for us. Pluswe have to solve the riddle."Jack rolled onto his side and tried to stand.

Crack.

"Uh-oh," he said. He went back down onto hisknees. "I think we're on thin ice.""What do you mean?" said Annie. She started tostand.

Another crack rang out.

"Uh-oh," she said.

She carefully lay back down.

The polar bear cubs moved closer to Jack andAnnie. They made little crying sounds.

Jack wanted to cry, too. But he took a deep breath.

"Let's see what our book says," he said.

He reached into his pack for the Arctic book. Hetook the masks out first and handed them to Annie.

"I took these from the igloo by mistake," he said.

As he started to reach for his Arctic book, he heardthe loudest crack of all.

CRACK!

'We're not even moving and the ice is cracking,"said Annie.

Just then, there was a new sound--a low, snortingsound. It came from the top of the snowbank, aboutfifty feet away.

Jack looked up.

Staring down at them was a bear.

"The polar bear mother," Annie. giant polarwhispered