Moselkern, Germany, July 1940

Maple leaves draped over the tree house window, the silvery fronds linked together like rings of chain mail to protect the boy and girl playing inside.

Dietmar Roth charged his wooden horse across the planks, knocking down two of the Roman horses with his toy knight as he rushed toward the tower of river stones. In his thirteen years, he'd become an expert on both knights and their armor. Metal rings were useless for protection on their own, but hundreds of these rings, woven tightly together, could withstand an opponent's arrows. Or sword.

Standing beside the tower, a miniature princess clutched in her hand, Brigitte yowled like a wildcat. As if she might really be carried away by warriors.

At the age of ten, Brigitte was an expert on royalty. And drama.

Instead of an army, Brigitte played with one toy — the princess Dietmar carved out of linden wood and painted for her last birthday. He liked renaming his knights, but Brigitte never changed the name of her toy.

Princess Adler.

Eagle.

Brigitte thought her princess could fly.

Dietmar drew a tin sword from his knight's scabbard and began to fight the black-cloaked opposition that advanced in his mind. Stretched across the tree house floor was an entire army of battlescarred knights, all of them with a different symbol painted on their crossbows. All of them fighting as one for the Order of the Ritterlichkeit. Chivalry.

He'd carved each of his knights' bows from cedar and strung them with hair from Fonzell, their family's horse — at least, Fonzell had been the Roth family horse until Herr Darre stole him away. Herr Darre was a German officer. And the Roths' neighbor. He was punishing Herr Roth for not bringing Dietmar to Deutsches Jungvolk — the weekly meetings for Germany's boys. Brigitte and her father were the only neighbors his family trusted anymore.

Dietmar was too old to be playing knights and princesses, but Brigitte never wanted to play anything else. And Dietmar didn't want to play with anyone else. He and Brigitte had been the best of friends since her family moved into the house across the woods six years ago, playing for hours along the stream until his father built the tree house for them. Their mothers had been best friends too until Frau Berthold died from influenza.

Once, Herr Berthold asked Dietmar to care for Brigitte if anything ever happened to him. Dietmar had solemnly promised the man that he'd never let anything or anyone harm his daughter. Not even an army of toy knights.

He lifted one of his knights off the horse. "Brigitte ..."

She shook her finger at him. "Princess Adler."

Cupping his other hand around his mouth, he pretended to shout, "Princess Adler, we've come to rescue you."

Brigitte flipped one of her amber-colored braids over her sleeve, calling back to him, "I will never leave my tower."

"But we must go," he commanded, "before the Romans arrive."

She feigned a sigh. "There's no one I trust."

Dietmar reached for Ulrich, the knight who'd sworn to protect the princess at any cost, and he solemnly bowed the soldier toward her. "You can trust me, Your Majesty."

"'Your Majesty' is how you address a queen," Brigitte whispered to him as if his words might offend the princess.

Dietmar knew how to address a queen, of course. He just liked to tease her.

With his thumb, he pounded the knight's chest. "I will protect you with my life."

Brigitte studied the knight for a moment and then smiled. "Very well. Perhaps I shall come out."

Outside their playhouse window, six rusty spoons hung in a circle, strung together with wire on a tree limb. The warm breeze rustled the branches, chiming the spoons, and Brigitte leaned her head outside to listen to their melody. The whole forest was an orchestra to her. The strings of sound a symphony. Brigitte heard music in the cadence of the river, the crackling of twigs, the rhythm of the wind.

Dietmar checked his watch. Only twenty minutes left to play before he started solving the geometry problems Frau Lyncker assigned him tonight. The world might be at war, but his mother still expected him to do schoolwork between four and five each afternoon. Even though everything outside their forest seemed to be foundering, his mother still hoped for their future. And she dreamed of a future filled with Frieden — peace — for her only child.

Brigitte leaned back in the window, her freckles glowing like a canvas of stars. "I shall make a wish on this tree, like Aschenputtel."

"Should I capture the evil stepsisters?" he asked.

At times it seemed the threads of imagination stitched around her mind like rings of armor, the world of pretend cushioning her sorrow and protecting her from a real enemy that threatened all the German children. She was on the cusp of becoming a woman, yet she clung to the fairy tales of childhood.

"I want you to capture the wind."

He laughed. "Another day, Brigitte."

Her fists balled up against her waist. "Princess Adler."

"Of course."

Her gaze traveled toward the ladder nailed to the opening in the tree house floor. "I'm hungry."

"You're always hungry," he teased.

"I wish we could find some Kuchen."

He nodded. Fruits and vegetables were hard enough to obtain in the village; sweets were impossible to find, reserved for the stomachs of Hitler's devoted. But his mother's garden was teeming with vegetables. He and his father had devised a wire cage of sorts over the plot to keep rabbits away, though there seemed to be fewer rabbits in the woods this summer. More people, he guessed, were eating them for supper.

He'd never tell Brigitte, but some nights he felt almost hungry enough to eat a rabbit too.

"I'll find us something better than cake."

He left Princess Adler and her wind chimes to climb down the ladder, rubbing his hand like he always did over the initials he'd carved into the base of the trunk. D. R. was on one side of the tree, B. B. on the other.

He trekked the grassy riverbank along the Elzbach, toward his family's cottage in the woods. Beside his mother's garden, he opened a door made of chicken wire and skimmed his hand across parsnips, onions, and celery until his fingers brushed over a willowy carrot top.

Three carrots later, he closed the wire door and started to march toward the back door of the cottage, the carrots dangling beside him. He'd bathe their dirt-caked skin in the sink before returning to battle. Then he'd —

A woman's scream echoed across the garden, and Dietmar froze. At first, in his confusion, he thought Brigitte was playing her princess game again, but the scream didn't come from the forest. The sound came from inside the house, through the open window of the sitting room.

Mama.

The woman screamed again, and he dropped the carrots. Raced toward the door.

Through the window, he saw the sterile black-and-silver Gestapo uniforms, bloodred bands around the sleeves. Herr Darre and another officer towered over his parents. Mama was on the sofa, and Papa ...

His father was unconscious on the floor.

"Where is the boy?" Herr Darre demanded.

"I don't know," Mama whispered.

Herr Darre raised his hand and slapped her.

Rage shot like an arrow through Dietmar's chest, his heart pounding as he...