"Wake up, Jack."
Jack opened his eyes. The light was dim outside his window. His sister, Annie, was standing by his bed.
"What's going on?" he asked.
"I heard a weird sound outside," said Annie. "And guess what I saw!"
"What?" said Jack.
"An eagle!" said Annie. "A huge eagle. It was sitting on top of the lamppost in our yard."
"No way," said Jack.
"Yes, way," said Annie.
"I'll bet Morgan sent him."
Jack sat up in bed. He threw off his covers. "I'm coming!" he said.
"Hurry. We have to get back home before Mom and Dad get up. Meet you on the porch." Annie slipped out of the room.
Jack climbed out of bed. He changed into his jeans, sweatshirt, and sneakers. He grabbed his backpack. Then he crept downstairs and went out to the front porch.
Annie was waiting in the chilly, damp air. Dawn was breaking.
"There!" she whispered. She pointed toward the lamppost in front of their house.
An eagle was perched on top. He was dark brown, except for a ring of golden-brown feathers around his neck. He stared at them with piercing eyes.
"Oh, man, that's a golden eagle," whispered Jack.
The eagle spread his wings. He rose into the early-morning sky and flew toward the woods.
"Follow him!" said Jack.
Jack and Annie ran down the porch steps. They crossed their yard and dashed down the sidewalk after the eagle.
"There!" said Annie, looking up. She pointed to the bird gliding above the Frog Creek woods.
Jack and Annie crossed the street. They hurried between the shadowy trees, until they came to the tallest oak.
"Whoa!" said Jack.
The eagle was perched on the roof of the magic tree house.
"Yay!" said Annie.
"You were right!" said Jack.
They climbed up the rope ladder and into the tree house.
Sunlight streamed onto the floor. It shined on two small wooden tablets. Next to the tablets was a scroll.
"A message from Morgan!" said Annie. She unrolled the scroll and read:

Land by the Danube
Many years ago.
Find a Roman legion camp
Dusted with snow.

"A Roman legion camp?" said Jack. "Really?"
"What's a legion?" said Annie.
"A legion is a unit in the ancient Roman army," said Jack. "A legion had almost six thousand warriors. The whole army had around 150,000 warriors. And--"
"Okay, got it," said Annie. "And what's the Danube?"
"It's a river that ran along the border of the Roman empire," said Jack. "That was almost two thousand years ago."
"How do you know all this?" said Annie.
"My school project on the Roman army," said Jack. "Remember that model of a camp I made? And I had to explain it to my class."
"Oh, yeah, I remember," said Annie.
"Rome had the best warriors in the world," said Jack. "They defended the Roman empire for over five hundred years! They--"
"Great, got it," said Annie. "There's more here from Morgan." She read from the scroll again:

You must each keep a journal.
Use tablets of wax.
With a pen called a stylus,
Write down the facts.

"So that's what this is!" said Jack. He grabbed one of the wooden tablets. "In ancient times, people wrote on these. See, the wood's covered with wax." He picked up a pointed reed. "And here's the stylus! It's like a pen with no ink!"
"Hold on," said Annie. "Listen to this."

Write what you see.
Write what you feel.
Do what warriors do
To make your words real.

"How do we 'do what warriors do'?" Jack said. "Roman warriors were the toughest guys on the planet. They had years of training."
"Maybe Morgan sent us something to give us magic skills," said Annie, "like the baseball caps we wore to be major league batboys."
They looked in the shadowy corners of the tree house. Jack saw only the Pennsylvania book that would bring them home.
"Nothing here," he said. "Morgan didn't even send a research book to help us."
"Don't worry, you know a lot from your project," said Annie.
"Not enough," said Jack.
"Well, maybe Morgan wants us to learn more on our own," said Annie. "Last verse."

Give the silver coin
To a hero in disguise.
He will share with you his wisdom.
Be home by moonrise.

"What silver coin?" said Annie.
They looked around the tree house again. Jack spotted a black coin on the floor. It was about the size of a quarter.
"Maybe this?" he said, picking it up.
"That doesn't look like silver," said Annie.
"Silver turns dark over time," said Jack. "You have to polish it."
"Okay, we can do that later. Let's go now!" said Annie.
"How?" said Jack. "There's no research book to take us to the right place."
"Hmm . . . ," said Annie. "I have an idea. I'll just point at Morgan's words." She touched the rhyme. "I wish we could go to a Roman legion camp on the Danube!"
A cry from the eagle pierced the air.
The wind started to blow.
The tree house started to spin.
It spun faster and faster.
Then everything was still.
Absolutely still.

---

Excerpted from Warriors in Winter by Mary Pope Osborne
All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.