August leaned against the table and took a closer look at the leather cover. “I never noticed this before!”

“What is it?” Charlie asked.

“At first, I thought the design on the cover had no rhyme or reason, just a decorative flair. But now I see what it is. Do you?”

Charlie held up the cover for both him and his mother to see. April spotted it first. “A colophon! It’s half of the one duplicated at the Library of Congress!”

“A what?”

“A printer’s mark,” August said. “Fust’s colophon.”

“Whose?”

“A man who helped print Gutenberg’s books.”

“I still don’t see it,” Charlie said.

“But what is it doing on the journal?” April wondered.

“Showing us where to look next? X marks the spot, right?”

“Someone tell me where it is!” Charlie was nearly in tears.

“Hold up the cover so it’s vertical,” April said, trying to calm him.

Charlie turned the leather ninety degrees.

“Now try to ignore the lines that are ornamental—the flowers and vines and boxes and circles, stuff like that—and concentrate on finding the letter in the middle. It crosses both the front and the back of the cover.”

Charlie squinted hard. “I see it!” he announced. “So what’s the X on there for?” he asked, his innocent curiosity a thankful redirect of the conversation.

“It was used by a man named Johann Fust,” April said. “He gave money to Gutenberg to help him print his Bibles. The X is actually the Greek letter chi, which was the symbol Fust chose to say, ‘Hey, I worked on this book.’”

“He should have used a jaguar instead.”

“A jaguar would have been great!”

“Okay, sorry to derail the tangent train, but we need to move on,” August said.

“You’re not being fun, Dad.”

“April, would you please explain to our son that our lives are in jeopardy here?”

“Why don’t you tell him?”

August shot a glare at his ex-wife, then turned to Charlie. “Our lives are in jeopardy,” he said.

“Dad, this isn’t helping. What do we need to do next?”

“Open the cover.”

Charlie turned the cover over and examined the damage where the pages had been torn away from the spine. The gash revealed a paper of a different color. He reached inside. “There’s something inside.”

“Be careful. Whatever it is has been in there a long time, so it’s probably pretty fragile.”

Charlie slowly retracted his hand. “I’m pretending that I’m playing that game Operation, but instead of just a buzzer going off, I die if I mess up.”

April’s expression crumpled. “That’s morbid.”

“But accurate,” August said.

Charlie’s hand emerged, his index and middle finger tweezing a folded piece of paper. He laid the item on the table, then carefully opened it.

“The tenth image,” August whispered.