Jack opened his eyes.

A thin gray light came through his window. Hisclock read 5 A.M. All was quiet.

Today we're going to ancient Ireland, he thought,back more than a thousand years.

Morgan le Fay had told him that it was a verydangerous time, with Vikings raiding the coasts.

"You awake?" came a whisper.

Annie stood in his doorway. She was dressed andready to go.

"Yeah, meet you outside," said Jack as he climbedout of bed.

He pulled on his jeans, T-shirt, and sneakers. Heput his secret library card into his backpack with hisnotebook and pencil. Then he hurried downstairs.

Annie was waiting for him in their yard.

The air was damp and misty.

"Ready?" she asked.

Jack took a deep breath.

"I guess," he said. He was a little worried about theVikings.

They walked silently over the dewy grass. Thenthey ran up their street and into the Frog Creekwoods.

Mist clung to the trees as they walked through thedark woods.

"It's hard to see," said Jack.

"Where's the tree house?" asked Annie.

"I have no idea," said Jack.

Just then something fell in front of them.

"Watch out!" shouted Jack. He covered his head.

"The ladder!" cried Annie. Jack opened his eyes.

The rope ladder from the magic tree house dangledin front of them.

Jack looked up. The tree house was hidden in themist.

"Come on, let's go," said Annie.

She grabbed the ladder and started up. Jackfollowed.

They climbed through the wet air and into the treehouse.

"Hello," said Morgan. "I'm glad to see you."She was sitting in the corner. At her feet were thescroll they'd brought back from Roman times and thebamboo book from ancient China.

"I'm so glad to see you," said Jack.

"Me too," said Annie.

"It's good that you both came early," said Morgan.

She reached into the folds of her robe and pulledout a piece of paper.

"Here's the ancient story you must find today," shesaid.

Morgan handed the paper to Jack. On it were thewords:

Serpens MagnaThe mysterious writing reminded Jack of thewriting from their trip to the Roman town of Pompeii.

"That looks like Latin," he said.

"Very good," said Morgan. "It is Latin.""But I thought they spoke Latin in ancient Rome,"said Annie. "Aren't we going to Ireland?""You are," said Morgan. "But during the Dark Agesin Europe, educated people wrote in Latin.""The Dark Ages?" said Jack.

"Yes," said Morgan. "The time after the fall of theRoman Empire.""Why is it called dark ?" said Jack.

"It was a difficult time," said Morgan. "People hadto work very hard just to feed and clothe themselves.

There was not a lot of time for playing, learning, ormaking art and music."Morgan pulled a book from her robe.

"Your research," she said, handing it to Annie. Thetitle read: Ireland Long Ago.

"Remember," said Morgan. "Your research book willguide you. But in your darkest hour--""Only the ancient story can save us," Jack andAnnie said together.

"And remember this," said Morgan. "It must be yourdarkest hour, when there is no hope left. If you askfor help too soon, it will not come.""And we have to find the story first," said Annie.

"That is true," said Morgan. "Do you have yoursecret library cards?"Jack and Annie nodded.

"Show them to the wisest person you meet," saidMorgan.

"Don't worry," said Annie. "I think we're readynow."Annie pointed at the cover of the Ireland book.

"I wish we could go there," she said. She gaveMorgan a little wave. "See you soon.""Good luck!" said Morgan.

The wind started to blow.

The tree house started to spin.

It spun faster and faster.

Then everything was still.

Absolutely still.