“Yes,” Hailey responded. “But according to the diary, and as the professor pointed out—Revere had never meant it to be cast, because the mold wasn’t really a mold at all. Apparently, it was a way of hiding a particular mathematical equation—which was supposed to lead to a mathematical solution. You see, the shape of the mold was actually an example of a branch of mathematics called ‘algebraic topology.’ It’s like writing an equation, but instead of using numbers, you use shapes. You know how you can use math to figure out the area inside a circle? Or how you can figure out the volume of a cylinder? This applies to more complex shapes.”

Nick was having an understandable amount of trouble keeping up. Hailey was so damn smart. Digesting all the information she’d gotten from the diary so quickly—it was boggling Nick’s mind.

“Alchemy is math, now?”

“Everything at its heart is math. Physics. Chemistry. And yes, alchemy. Take turning lead into gold. Lead is an element—you remember the periodic table? Gold is also an element. At the atomic level, they’re differentiated by three protons. Lead has three more protons than gold. To turn lead into gold, all you need to do is knock out those three protons.”

“Which is impossible,” Nick said.

“Not at all. In fact, it’s been done before. Or something very close to it. Thirty years ago, scientists at the Lawrence Berkeley National Laboratory used a particle accelerator to blast a sample of bismuth, which is right next to lead on the periodic table. The accelerator knocked away two protons, turning the bismuth into gold. It takes an immense amount of power—nuclear-fission level power—to transform metals, but it is indeed possible. Prohibitively expensive, and only on a limited scale, but yes, scientists can turn lead into gold. But I wouldn’t call a nuclear reactor the philosopher’s stone.”

Nick raised his eyebrows, until Adrian reluctantly stepped in.

“It’s what the alchemists called their Holy Grail: some sort of device or substance that could transform metals. Nonsense, of course. Most alchemists described it as a rock or powder—”

“According to this diary,” Hailey interrupted, before the professor could go down a winding path, “Revere believed it was a mathematical equation, not a powder. Thomire was skeptical; how could a mathematical equation turn lead into gold? Even though he’d taken the mold and cast it into this bronze eagle, he couldn’t figure out the answer. But he did find one more clue. According to the last pages of Thomire’s diary, Revere’s experiments in alchemy did not end with the eagle’s mold. There was a second part—‘deuxième partie’—information without which the eagle was useless. Contained in the curves and swirls somewhere within the shape of the eagle was the mathematical equation, the blueprint—but its solution was somewhere else.”