“Maybe that’s the automaton’s brain.”

“That depends on when it was made. In the early sixteenth century, people still didn’t understand the brain. Many scientists, da Vinci among them, thought the brain was the seat of the soul.” If Gutenberg had subscribed to such beliefs, this wouldn’t necessarily be the source of the automaton’s artificial thoughts, but the metaphorical heart of its magic.

I slid the gears onto either side of the horizontal rod. A smaller gear added a pair of Ns. A sharp-toothed crown-wheel escapement slid over the top of the vertical rod, bringing an H-A. I rotated them together until the letters lined up: JOHANN.

“Gutenberg wouldn’t be the first artist to autograph his work,” Lena suggested.

I pointed to the S-T on the second disk. “We’re missing a piece.”

It was Lena who found the thick cylinder, an inch-high pipe with a jagged upper edge and a magnificently carved F, followed by a smaller U.

I disassembled the disks, sliding the cylinder over the central rod, then pushing the rest into place. Rotating one disk moved the other, and as I lined up the first name, the second came together below. “Oh, God.”

“Who was Johann Fust?”

“A businessman,” I whispered. “An investor who helped to fund Gutenberg’s press. Gutenberg failed to repay the loan, so Fust ended up suing him. The details are scarce, but Fust nearly destroyed him. According to some historians, Fust took Gutenberg’s equipment as payment for that debt. One way or another, Fust then went on to set up his own press.” The gears in my hand twitched, rotating a single click on their own.

“Do you think Fust made the automatons?”

“No. I think this automaton is Fust.” I sat back, staring at the broken figure. “Libriomancers cheat,” I said numbly. We weren’t strong enough to work magic any other way. As a traditional sorcerer, Gutenberg had been a failure, so he had spent his life finding another path to power. “He used the magic of the Bible to define his automatons, to give them their powers, but he’s not God. He couldn’t give them life, or the independence they needed in order to fight his enemies.”

“So he used people?” Lena stared at the automaton in horror. “Which means when I dragged that thing into the tree with me, I killed it.”

“Or you freed it.” The gears clicked again. “Fust supposedly died of the plague. Gutenberg must have gone to him just before he died.”

Had he revealed his power? Offered Fust the chance to live free of the pain? Death from plague was a nasty way to go. Or had Gutenberg simply ripped Fust’s spirit from his body, trapping it in a mechanical head.

“He enslaved them,” said Lena. “Isaac, what happens to Fust if we repair this thing? If he’s finally at peace, are we dragging him back into servitude?”