His mother had a thimble in her sewing box. But this was different. Dangerous. It held something. Something . . . sad. He concentrated all his energy there. Something lost. Something unfinished. It throbbed like the heartbeat of the castle itself. It throbbed with an ancient longing.

The thimble became a ball of light, brilliant, painful. And needy, desperate, grasping, and then the wolves were howling, howling, and the trees banged as if in a high wind against the windows and doors of the castle, and Isaac knew he’d shifted from channeling good magic to bad. Evil magic was flowing from inside the thimble to Isaac.

He pushed back and sent the evil magic reeling. The wolves and trees slowly went silent. The darkness lifted a little. Isaac’s head ached.

Kat, trembling, pocketed the chatelaine. “Well,” she said, and leaned against a table. “Goodness.”

“That . . . whatever it is,” Isaac said. “Whatever’s inside.” He rubbed his temples, trying to calm the ache. “Now, that’s definitely bad magic.”

“It’s the soul of a witch,” Kat said, sounding exhausted.

“The soul of a what?” Isaac said, shocked.

“Remember what I said about what happened here a couple of years ago?” Amelie said. “About the monster who tried to steal our souls?”

Isaac nodded.

“That’s the monster. She was the Lady Eleanor. Kat was able to capture her soul instead, inside the thimble.”

Isaac gave a low whistle. “No wonder it sends out so much . . . anger.”

“She only wanted one thing, really. But she didn’t know how to get it without hurting others.” Kat took a deep breath. “I think we’re done for now.”

He nodded. “I agree.” Then, “Kat?”

“Yes?”

“Thank you. I mean it.” He rubbed his sweaty hands on his pants. “I still don’t know exactly why my parents sent me to Rookskill, but I am glad they did. Really glad. Glad to know all of you. Glad you’re here and willing to help me. Glad you’re my friends.” He paused. “So, um, thanks to you. Again.”

Kat smiled, for the first time in Isaac’s memory. “You’re welcome.” She pushed away and walked unsteadily out of the library.

Isaac turned to Amelie. “What do you think?”

“I think you have quite a gift.”

He shook his head. “I wish I knew more about this. About myself. About where this gift came from. And why.”

“I don’t know about the why. But maybe you inherited it?”

In his mind’s eye, Isaac pictured his mother standing protectively in the doorway of the hut, whispering.

“Maybe,” he said, pacing away, staring out the vine-covered window at the gloomy forest beyond.