“That could be why he stole those books from the archive,” Lena said. “Not to use their magic, but to figure out how to reverse a magical lock. If there are others like Hubert, he could be planning to help them.”

“Or he could be trying to reverse engineer the process, to find a way to do to Gutenberg and the rest of the Porters what they did to him.” I needed time to process everything, to sort through the various pieces, but one significant question remained unanswered. “I reached through one of those books, trying to find Hubert. He sent something back after me. Something that felt alive, made of hatred and desperate hunger. I’ve never felt magic like that, powerful enough to wipe me out of existence as casually as you or I might slap a mosquito.”

The last traces of humor vanished from de Leon’s face. When he spoke, he was as cold and sober as I had ever seen. “You are a very fortunate man, Isaac Vainio. Do the Porters know about this?”

“We told Nicola Pallas what happened,” said Lena.

I saw comprehension in his eyes. “She forbade you from leaving, didn’t she? And you defied her.”

“You know what that was. What Hubert conjured up to destroy me.”

The muscles in de Leon’s jaw twitched, like he was struggling to speak. He shouted in frustration, then threw back his head and laughed bitterly. “Johannes, you fool!” His hands seemed to grab the sides of the mirror, and he leaned in close. “I would tell you what it is you face, and perhaps even help you to survive your next encounter long enough to save Gutenberg’s life. Only Gutenberg’s own geis prevents me.” Another laugh, this one softer. “He would have appreciated the irony, I think.”

“So why aren’t the Porters doing more?” Lena asked.

“‘Why do the other pieces stay behind?’ ask the pawns.” De Leon chuckled and brushed his mustache with thumb and forefinger. “The Porters are doing what they have always done. They are preparing to eliminate the threat and contain the damage, once you or another of their pawns flush out their quarry. Only I’m afraid they underestimate the danger. With Gutenberg gone, there’s not a single one who remembers . . .”

“Remembers what?” I demanded.

“Find Gutenberg,” de Leon said urgently. “If the thing you saw enters his mind, then what you experienced will be a mere hint of the suffering to come.”

“What is it?” I asked. “Where did it come from, and if the Porters know about this threat, why hasn’t that information been shared?”

“Those, Isaac Vainio, are some of the many questions that led to my eventual departure from the Porters.” He moved closer, until his eyes filled the mirror. “If you fail to rescue Gutenberg,” de Leon said softly, “then I promise whatever is left of you will answer to me.”

He disappeared before I could respond.