The creature straightens with a barely audible snarl and stands for another moment before it lifts into the air on black wings that are each as big as a tall man, casting a chill shadow upon the city below.

The prowling cat, as it happens, crosses the Charles Bridge just as the great wings open. But even if the cat had lifted its head and looked all the way up to the top of the tower, it would have seen nothing but a mist. Nothing but a dark, evanescent blot against the starless sky.

Nothing.

Oh, except . . .

Except, had the hunter turned and looked down, the cat might have seen two red eyes, eyes as red as fire, as red as blood, as red as rage.

CHAPTER 2

Isaac

1942

Isaac Wolf lay on his stomach, propped on his elbows, book open before him. Shelley’s Frankenstein.

Yes, he read it because it helped him with his English, but this story about a scientist who found the secret of creation and made a monster, that’s what grabbed at Isaac’s heart. It gave him shivers but also made him wonder: Why did he feel sorry for the monster? Would Isaac have acted differently from Victor—treated the monster differently—and so maybe saved his friends? Reading this book plunged Isaac into a realm so darkly magical he was lost inside it, and coming out, wanted to dive right back in.

He rolled over and sat up, rubbing his eyes, returning to the real world. The world of war.

It was an afternoon of filmy gray light.

Last night he’d heard a noise and was up like a shot. He’d held his breath, straining to hear. The sound of a door closing? The distant, soft chime of a bell? But he heard no more in the deep and snowy silence, and he sank back into his bed, to his dreams of chasing strange creatures through shadowy forests.

A wolf should be a hero in a grand tale. That’s what Isaac wanted to be. Was sure he could be, one day. Maybe he could become a spy and that would be his spy name. He traced the name Wolf with his finger in the air.

But Prague had been made fearful since the Nazis had come. People were anxious, secretive, huddled into themselves as they hastened through near-empty streets. His school was closed. His teacher’s sister, Miss Rachel, sobbing, had shooed all the boys away, telling them to go, now, go straight home now, don’t stop. He’d gone and he’d stayed put, because he was afraid of the Nazis, too.

One by one, his friends and neighbors had disappeared. Some had been “relocated.” Isaac had guessed what being relocated meant—it meant that the forces of darkness were washing over all the world.