It was about ten minutes later when Hailey glanced up from the phone and the book with an expression that could only be described as bewildered.

“It’s a diary—not by Lafayette or Paul Revere. It was apparently written by a man named Pierre-Philippe Thomire.”

“The sculptor,” Adrian said.

When neither Hailey nor Nick seemed to recognize the name, Adrian gave them a stare that Nick guessed was usually reserved for freshmen who were about to fail his class.

“One of the most prominent French sculptors, who worked mostly in Paris during the early nineteenth century. A favorite of the emperor, Thomire also made many pieces for Marie Antoinette. He was proficient with bronze—perhaps the greatest bronzier of his era.”

Hailey glanced at her backpack, where the wing of the eagle finial was still visible.

“Indeed,” Adrian said. “Thomire was also a noted colleague of Lafayette’s. He traveled with the war hero when Lafayette came to the Americas to lay the cornerstone of the Bunker Hill Monument.”

“And that’s when he put the key on the urn?” Nick asked.

“Presumably,” Hailey said. “This diary was written here, too—but earlier, during a short sabbatical Thomire had taken after his sixty-third birthday. It was the summer of 1814—the same year the eagle was made.”

According to the diary, she continued, Thomire had come to Boston to spend a week in the workshop of the most famous metalworker in the fledgling American republic.

“Revere?” Adrian coughed. “But there’s nothing in the historical literature—”

“I can’t speak to that,” Hailey said. “But if this diary is real—this is where things get really strange.”

According to Thomire’s diary, he hadn’t visited Revere simply because Revere was the foremost metallurgist in the country—the only person in the Americas who had figured out how to work with sheets of copper, and the top expert on bronze and engraving—but because Thomire and Revere shared another passion.

“‘Le monde secret de l’alchimie,’” Hailey read, from the diary. “If the translation software is working correctly, he’s talking about alchemy.”

Adrian coughed again, shaking his head. Nick looked at him, then at Hailey. Alchemy. He’d heard the word before.

“Like, turning lead into gold.”

“It’s a strange, cultish endeavor that goes back thousands of years,” Hailey said. “When I first got interested in science, I read about it pretty extensively. The prescience stuff you and I talked about at MIT—well, alchemy goes back even farther than most of that—farther back than the origins of chemistry, even way beyond chymistry. It began in ancient Egypt but has been practiced throughout time. A handful of famous scientists in history were secret alchemists. Newton was perhaps the best known. When I said he came to his conclusions about light being broken up into more basic elements—that comes from alchemy. But Newton wasn’t the only famous historical alchemist—there were many others.”