“What if I helped?” Isaac asked Lark. “What if I amplified your spell?”

“Oh,” said Lark, coming to his side. “Oh, yes, please.”

Lark leaned over and began whispering, and Isaac felt the hum at once. He channeled it right through his heart. When he did that, he could direct it, an electrical charge over which he had control. He focused Lark’s magic with all the emotion and energy he could manage.

“Wow,” Kat whispered.

“Goodness,” from Willow.

And then, “Hullo?” It was Amelie. “Isaac?”

Isaac grinned and she smiled back and he was warm all over. Everything around her—everything around him and Lark, too—glowed blue as if they radiated intense energy. The magic buzzed inside Isaac, slowly fading away.

He had power. He used magic. He was part fae, but he didn’t have to be a monster.

Amelie sat up slowly. “What happened? I only remember how it was so dark.”

“Moloch,” Isaac said. “That’s his name. He’s an Unseelie fae. He spelled you to get to me.”

“But, why?” said Kat.

“Because I have the key to the Vault of magical artifacts.”

“Yes!” said Leo.

“My father gave me the key, and, Leo, you were right. The Vault comes to the command of the Guardian who has the key. Which is what Moloch wants. When my father gave me the key, he made me the new Guardian.”

“Oh, but, wait,” said Leo, agitated. “That’s not quite right. Not from what I read. Not quite.”

“Um, but . . .” Isaac paused. “What is it, Leo?”

“This is important,” Leo said, pacing. “You have to accept. You have to finish the spell.”

“Finish the spell,” Isaac echoed, remembering Moloch.

“Right. You aren’t the Guardian yet, officially, until you finish the spell. This is a very dangerous spot to be in. If Moloch gets inside with the key before you finish the spell—rather like taking an oath, but it has to be done inside the Vault—then he’ll be able to become the Guardian. And because he wouldn’t hesitate to use the artifacts for whatever evil purpose, he could be the most powerful being in both the fae and human worlds.”

There was a long silence.

Until something thudded against the door.

*   *   *

“Salt,” Willow cried out. “Quick! Salt and iron.”

“Oh,” Lark cried. “Of course.” She ran to a shelf and yanked at a burlap bag, then dragged it to the door and began spilling a thin trail of salt across the threshold.

Kat grabbed a great iron frying pan, wielding it like a tennis racquet.

The door shuddered, with a boom, boom.

“If we can get to the armory,” Isaac said, “we’ll have all sorts of iron in addition to reinforcements.”

“What armory?” Amelie asked.

“Very, very deep,” Willow said. “An ancient part of Rookskill. Now with bright swords buried there in the deepest part of the castle.”