Isaac took a deep breath. He focused on the magic in Kat’s hand. He felt a sharp pain, and then a shift, and then, yes, energy zinged through him, from his head to his feet and back again. He closed his eyes and concentrated.

The pain was terrible, as if he was being torn to shreds, his skin bleeding from a thousand paper cuts, his veins on fire. But he refused to give in to it.

He refused to give up.

He thought about his parents, somewhere in time. About how they’d given him a responsibility to discover who and what he was and what he could do, and he decided—right then—that no matter how it hurt, he would never give up.

Never.

Little by little he could sense the magic. The two opposite magics, light and dark, good and evil. Little by little he could isolate them as if magic was a thread that ran from his brain to his hands. He took hold of that thread and pulled and then . . .

. . . and then he had control. He could choose the good magic if he wanted.

It was almost too much. It zapped and zinged, but he was also strong, and he pulled himself straight to his full height. He concentrated on the good, bright magic, fighting the other, which surged against him like a wave pounding a cliff.

“Ah!” Kat cried. He opened his eyes. Her face was contorted by pain. She held out her fist, glowing with a blue flame. “I can’t let go!”

Leo pulled at Baines.

“Really, now. Stop this nonsense,” Baines said. Colin, staring at the wolves, muttered under his breath. Amelie tugged at both Kat and Isaac.

They reached the castle wall.

Isaac turned and tripped and stumbled, and lost concentration, and then, lost control.

The pain in his head became unbearable again. He froze, flattening his back against the hard, cold stone wall, pressing against it as if he could push himself through.

Ahead of him, Baines, Leo, Colin, and Amelie tumbled inside the castle door.

“Kat,” Isaac cried. The wolves all began to howl at once. Terror filled him. Blind terror. He had to disappear.

She turned. “Isaac, where are you?” She looked right through him. As if he was invisible.

He reached out his hand. “I’m here.”

She squinted, searching.

He closed his eyes and concentrated again. It must be the fear, he thought. I wanted to disappear, and I did.

When he opened his eyes, Kat’s eyes widened. “Wow. For a moment there, you vanished.”

They both heard the movement of the wolves, making through the brush straight for them.

Kat reached for him. “Run!” she cried, and jerked his arm. He turned, slipped, stumbled again, nearly falling before he could get his gangly legs under him. Then he ran.